Constraint: U459 hole closer than 0.25mm to PTH

Upverter Support
#1

I am confounded. I don’t know what this constraint means or how to fix it.

I forked a good design (to keep a copy of the A version we sent to the PCB maker), and then am using this B version (from the fork) for enhancements, and for implementing fixes should we find bugs in the first PCB. I made a few changes in the B version in the corners, none of which involved the components called out in the constraints.

U459 is a 14 pin DIP package with pin-through-hole (PTH) leads. We have a bunch of these ICs on the PCB and all have the same constraint. The A version had no problems.

Any ideas?

#2

I have stumbled across additional clues as to what might be causing the above. The message I get above (“U459 hole closer than 0.25mm to PTH”, but is found in 38 places for the Uxxx components) is somehow related to non-plated holes I put in the corners of the boards. These non-plated holes will be for screws, for mounting the PCB. If I remove the 4 non-plated holes, the 38 constraints disappear. The non-plated hole has none for a Net Attachment.

I have altered the pour outline in one corner so that there is no pour layer (either top or bottom) where I have the hole. I then added a non-plated hole to that unpoured area. I still get the constraint.

When does the constraint appear? When I add the hole, I do not get the constraint. When I log off upverter and come back later to logon, then the constraint is there.

I have put non-plated holes in the 4 corners of another PCB and did not have this issue. The parameters I selected for the non-plated hole on this PCB are the same as on the PCB that worked. So I am a bit perplexed.

#3

Hi Cloudwatcher. I am currently in the process of bringing the forum up to date so I wanted to wake this thread. Have you looked into this any further? If this is a showcase project, could you point me to it?

#4

Hi Keith-lee-gstix,

This is not a showcase project, although it may fit or qualify for that designation since it has over 400 parts on it. Have I looked into this any further? I have not.

With the coronavirus shutdown on university campuses, research involving lab work (hands on) has come to a screeching halt. So this project is on hold. We were populating the original PCB so we could test it. After testing, so we knew our circuits were good (or we got bugs fixed), we were going to make final updates, fixes, and improvements and then send out the PCB again for final manufacture. This work stopped in March 2020. So we are presently on hold.

Because of your prompt, I went back to the design and looked at it (our ‘B’ version). It still has the 41 unexplained ‘constraints’. If these do not prevent manufacture, these constraints are not an issue. 40 of the 41 constraints are for the same reason - the hole of some 14-pin DIP is closer than 0.25mm to PTH.

#5

One thing you could try is the ‘renumber refDes’ script. I am still discovering the nuances of Upverter myself, but the script seems to be a nice way of forcing the tool to examine each component on the board.
The other option is to manually edit the constraint list to make sure this constraint is no longer relevant.
I’ve pointed the dev team to this post, but because it’s such a design-specific issue, I’m guessing it will be hard to replicate.

#7

Hi keith-lee-gstix,

I have the problem again. It is on both 8-pin and 14-pin through hole ICs. I have not yet tried the ‘renumber refDes’ script suggestion you have - don’t know what this is, but I will look to see if I can find it. The problem is occuring on all 13 of the 8-pin ICs, and on 4 of the 12 14-pin ICs. The problem is not on every pin.

Also I am willing to share this with the dev team if they want to look at it, but I will need instructions on how to share it.

#8

Tried the renumber refDes script, and it messed up our numbering scheme for all our parts, so I had to go to History and reverse this.

So some other solution is needed. The developers of the Upverter software put this message in for a reason. I wonder if they could shed light on what the software has found or is looking at when it emits the “Unn hole closer than 0.25mm to PTH” message.

#9

I guess a bottom line is this: Since I cannot visibly see any ‘real’ issues related to this message, there is nothing about the PCB that makes it non-manufacturable, then it probably is manufacturable.
So perhaps the best thing to do is to click on the eyeball (to the right) for each constraint having this message - I have 25 of these constraints, one for each IC on my PCB - b/c this will put the constraint count to zero. Or alternatively, ignore the constraint and see if Upverter will still create a Gerber file.

I assume if Upverter will make a Gerber file, it has passed its ‘manufacturability’ tests. After all, the primary thing we want is to be able to make the PCB.