Hi all,
i need to create a particular edge board cards, tipical of modules soldered directly over another board. Is how to have a hole in the external board edge, but this create an error. And is not possible to cut the board …
See the picture .
I can create this in kicad ?
Application: kicad
Version: (5.1.2)-1, release build
Libraries:
wxWidgets 3.0.4
libcurl/7.61.1 OpenSSL/1.1.1 (WinSSL) zlib/1.2.11 brotli/1.0.6 libidn2/2.0.5 libpsl/0.20.2 (+libidn2/2.0.5) nghttp2/1.34.0
Platform: Windows 7 (build 7601, Service Pack 1), 64-bit edition, 64 bit, Little endian, wxMSW
Build Info:
wxWidgets: 3.0.4 (wchar_t,wx containers,compatible with 2.8)
Boost: 1.68.0
OpenCASCADE Community Edition: 6.9.1
Curl: 7.61.1
Compiler: GCC 8.2.0 with C++ ABI 1013
I have patents on Connectors and was Director of Engineering and Plating at one of worlds largest connector companies and Sr. Engr at another. We hated, hated doing side plating (at the time 15yrs ago) the process produced too much product loss.
In General: With respect to Connectors: It’s all about the “Normal Force” of the Connector’s contact applied to the contact on the PCB.
With Contact points on Top and/or Bottom of PCB, the Normal force is ‘pinching’ the PCB.
If there’s a side contact point, it’s Normal force wants to push the PCB and Connector apart. Thus, connector needs a locking feature.
I won’t go into it - folks like me earn phD’s doing this stuff so, there’s tons of info out there…
Kicad doesn’t make Connectors, it makes PCB Gerbers. But, you can make a connector to use in Kicad and FreeCad is a good choice for that.
Also, you can make a PCB in FreeCad to use in Kicad as a part footprint. But, it’s only for graphic use. Can also use the Stepup plugin to export the PCB for use in Kicad…
A quick graphic example of concept of sideplated in FreeCad - attached. No intention to real engineer it, just enough to convey the point.
Lastly, if the only reason to use a connector with Edge contacts as part of the contact on Top and/or Bottom, is because you ‘think’ it’s better. Consider the application of it… Micro-stitial Fretting versus zero/minimal benefit is not worth it.
Cartoon attached of Normal Forces - you can imagine… Including the extra cost for Stamping Die…
Just my opinion…
[EDIT] Oh, and Connector with Edge contact will work with a PCB not having Edge contact.
The picture that the OP posted appears to be castellated pads as @hermit mentions. With this type of pad the board edge routing bisects a PTH. Some MFGs will refuse to do this. My uninformed suspicion they don’t want to keep their milling bits sharp enough and/or feed rates slow enough to cut without tearing the copper and through-hole plating. Because it is a specialty operation, you would have to check with the specific manufacturer on how they want the intent communicated to them, and to know how to work around (or ignore) those specific hole to edge clearance DRC hits in their automated software.
Yes, this stresses the plating, which is why it is a good idea to have another hole as well, so that the sawn-hole is not relied on to provide the top-bottom connection.
I have done it (in Protel) by just having a pad extended off board edge (like was told by PCB manufacturer to do it).
I suppose the problem in KiCad would be DRC will complain.
If I would need to do it in KiCad and I would like to have no DRC complains I would probably draw PCB edge at another layer and just send it to manufacturer instead of Edge.Cuts.
Or may be it is possible (don’t know) to block that complain or define somewhere the minimum distance between copper and edge to be 0 or less then 0.
It seems at some point in time I used software that let you tick off boxes to ignore specific violations. Anyone know if this is in the roadmap for KiCAD?
