I don't know the board-positioning details of your system, but I've seen PCB mounting holes for screwing the board onto chassis studs that allowed more than .050" "wiggle-room" for the PCB placement. Make sure you take the worst-case physical mounting of both boards into account as you evaluate your contact engagement between your two connectors.
Later,
Carl
Carl B. Van Wormer, P.E., AE7GD
Senior Hardware Engineer
Cipher Engineering LLC
[log in to unmask] https://www.cipherengineering.com/
503-617-7447x303
8295 NE Evergreen Pkwy, Ste 209
Hillsboro, OR 97124-6317
This message may contain confidential and/or proprietary information, and is intended for the person/entity to whom it was originally addressed. Any use by others is strictly prohibited. If I sent this to you by mistake, please be nice and delete it, and then tell me of my mistake so I can send it to the right person.
-----Original Message-----
From: TechNet <[log in to unmask]> On Behalf Of Decker, Scott Collins
Sent: Wednesday, February 24, 2021 7:52 AM
To: [log in to unmask]
Subject: Re: [TN] PCB Question
Steven,
The positional tolerance for the holes should be .006" from true position if they are using GDT. Vendors will hit that much better in most cases, but depending on how they drill the stack and other factors, the .006" is a good number with the likelihood of them being closer. The typical tooling hole tolerance is .002" for holes less than .100" so a typical tooling hole of either .062 or .100 should be .002". (That's what I/we use) The artwork side for what you're doing shouldn't matter much because you're looking at the mechanical side of things. That said, if the hole locations are .006 and depending on the class of the board, to meet the minimum annular ring value, the vendor is going to locate the artwork such that they don't violate breakout or annular ring requirements. That's my simple take on this, I hope it helps some. Stay Safe and healthy.
Later...
Scott Decker | Senior Engineer, PCB Design Services CID+ | Electronic Systems Center COLLINS AEROSPACE
3445 S. 5th Street, Suite 170, Phoenix, AZ 85040 U.S.A.
Tel: 602 308 5957 FAX: 602 243 2347
[log in to unmask] www.collinsaerospace.com [collinsaerospace.com] KE7MWT CONFIDENTIALITY WARNING: This message may contain proprietary and/or privileged information of Collins Aerospace Systems and its affiliated companies. If you are not the intended recipient please 1) do not disclose, copy, distribute or use this message or its contents, 2) advise the sender by return e-mail, and 3) delete all copies (including all
attachments) from your computer. Your cooperation is greatly appreciated.
-----Original Message-----
From: TechNet <[log in to unmask]> On Behalf Of Vargas, Stephen M
Sent: Wednesday, February 24, 2021 7:00 AM
To: [log in to unmask]
Subject: [External] [TN] PCB Question
Good morning, a question arose where I need some help. We have a PCB which mounts into a chassis then mates to another board in the same chassis via a right angle male header to a female connector. The issue is that the male connector does not protrude fully into the female connector. We know the issue is that the spacing between the two boards is incorrect, but we'd like to do a full dimensional tolerance analysis to determine the optimal spacing. One question that arose which I cannot answer and I'm hoping to get some assistance with, is related to the PCB artwork to PCB tooling hole registration/tolerance. I did a quick look through many of the IPC board specifications, but wasn't able to find anything. I'm thinking my searching skills are waning, so I'd like to get some help from this group. Thanks in advance.
Regards,
Steve Vargas
|
