Electronics > KiCad
A new pad property warning
ataradov:
Here is the exact connector I use in all my designs https://www.lcsc.com/product-detail/USB-Connectors_XUNPU-TYPEC-304J-BCP16_C2835315.html
I don't have a public library, but you can extract the footprint that works with all the regular manufacturers from one of my project. This one, for example https://github.com/ataradov/free-dap/tree/master/hardware/d11-nano-dbg
ksjh:
--- Quote from: Jonathon_Doran on July 08, 2024, 06:25:58 pm ---They do not meet JLCPCB's capabilities.
--- End quote ---
And yet, I just hand-soldered a prototype PCB with exactly the footprint I mentioned earlier. The PCB was manufactured by JLCPCB without any complaints. Since I used some 0402 resistors, I had to use the microscope anyway and thus could inspect the USB footprint on the manufactured PCBs in detail. In this and all of the previous orders from JLCPCB, I did never see any problems with this footprint, even so it violates the official limits. For production runs, I would be more careful, but for prototyping, it was fine to simply go with the standard KiCad footprint. I used the connector the KiCad footprint is intended for this time, https://www.lcsc.com/product-detail/USB-Connectors_G-Switch-GT-USB-7010ASV_C2988369.html, but have also used the same footprint for even cheaper ones like https://www.lcsc.com/product-detail/USB-Connectors_DEALON-USB-TYPE-C-018_C2927038.html. I think Alex is right, I also believe this is one of the most generic USB-C footprints.
EDIT: I attached some PCB photos. As you can see, using the mentioned footprint, some of the SMD pads adjacent to the NPTH lost some copper in the corners during the manufacturing process by JLCPCB, but this is nothing that bothers me or caused me any problems for soldering. But I am not sure how a stencil would look like.
ksjh:
--- Quote from: Jonathon_Doran on July 08, 2024, 06:25:58 pm ---There was one 16-Pin connector in the symbol library, and it doesn't match any of the connectors that I find in stock at JLCPCB.
My next plan is just to make my own symbol.
--- End quote ---
Why? What part of the symbol did not match?
--- Quote from: Jonathon_Doran on July 08, 2024, 06:25:58 pm ---The connector is on the edge, but the footprint that I found (that matched the exact manufacturer and part# of an available connector at JLCPCB) had edge cuts for the shield holes. These were not on the edge of the board, so were in the interior (middle) of the board. KiCad did not like this, and I don't blame it. The connector was on the edge, sitting a bit over it to be honest.
The cuts were in the edge cuts layer.
--- End quote ---
Perhaps there was another problem with this footprint, but this is exactly how to specify routed slots in KiCad. Not only should this not cause any errors, it is simply the right way to do it.
--- Quote from: Jonathon_Doran on July 08, 2024, 06:25:58 pm ---There is no symbol to match it, but that is an easy fix. In the time that I've spent trying to make the wrong footprint work I could have made 100 symbols.
--- End quote ---
Again, why? Electrically, it is the same 16 pin USB-C connector. Why do you see the need to create another symbol? What is wrong with using USB_C_Receptacle_USB2.0_16P?
--- Quote from: Jonathon_Doran on July 08, 2024, 06:25:58 pm ---Also, as I look at the picture of this connector, there are metal tabs that look like they might need to sink into the board. How do you handle these?
--- End quote ---
Hm? This is what the plated routed slots are for (those on the EdgeCuts layer). Or do you mean something else?
Jonathon_Doran:
Please keep in mind that I am new to this, and so I don't know what compromises/changes can be made. Unless everything matches, I'm convinced the project will catch fire and kill my pets.
The symbol for a 16Pin does not have the MID pins for one. The footprint did, but not the symbol. Not a big deal. I'll look at your connector and footprint (thanks much!). What I saw on my previous attempts was that the cutouts would fail DRC because of edge cuts not being contiguous. There was also a failure due to some pads being too close to drilled holes under the connector.
I first looked at this Hirose part (C2889324), and the datasheet had pins that was not on the EasyEDA footprint/symbol (linked from JLCPCB). So I went in search of other parts. This Shou Han part looks good (#C668624). But the footprint is a bit different. This is what I was trying to layout last night. I have no way of knowing which footprint in the KiCad library would be appropriate for this. That is why I went off in search for another source, and eventually just installed EasyEDA and exported the footprint. I now learn that was a bad idea. I was starting to think I should find a part that was available at Mouser, buy one, and go to town with some calipers.
I could just see JLCPCB saying "no" to that, and I wouldn't have a clue how to respond.
But not matching the connector (to me) means that there would have to be a perfect match. And I was hampered by not being able to find many connectors in stock there. Using LCSC's search engine has made my life a lot easier. Sometimes just knowing a part number makes a whole world of difference. "Nope, don't have any"... "What about part #xxxxxxx?".... "Oh, yeah, we have 2000 of them."
I feel like I am learning a lot about how to negotiate this process.
Sorry to ask so many beginner questions. I wouldn't attempt something like this, but Logitech discontinued my favorite keyboards. If anything happens to the ones I have (that still work) then I am in dire straits.
I just have a few things to clean up, and then I can submit the design in the projects forum for public comment. I have spent weeks on this thing, and it isn't that complicated!
ataradov:
--- Quote from: Jonathon_Doran on July 08, 2024, 11:10:30 pm ---The symbol for a 16Pin does not have the MID pins for one.
--- End quote ---
What are "MID" pins?
--- Quote from: Jonathon_Doran on July 08, 2024, 11:10:30 pm ---I first looked at this Hirose part (C2889324)
--- End quote ---
This is a midplane mount connector, it needs a board cut out and the connector is physically located in the board plane, not on top of it.
--- Quote from: Jonathon_Doran on July 08, 2024, 11:10:30 pm ---This Shou Han part looks good (#C668624).
--- End quote ---
This is the same generic connector size/pinout. If a connector visually looks like this one, it will be the standard size. Connector manufacturers are not stupid, they won't make parts that are almost the same, but slightly different. They all want to replace competition in the product, and designing compatible parts is a way to go here.
--- Quote from: Jonathon_Doran on July 08, 2024, 11:10:30 pm ---I could just see JLCPCB saying "no" to that, and I wouldn't have a clue how to respond.
--- End quote ---
You fix what they say is wrong. They won't just say "no" without explanations.
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