Where location tolerance is critical use supported hole and with lands
it to ease PCB fabrication. When unsupported land should be used and
when land is not feasible design hole as supported.
Jeffrey Bush
Sr. Principle Product Assurance Engineer
Space Systems and Electronics - Performance Excellence
BAE SYSTEMS
P.O. Box 868, MER24-116A
Nashua, NH 03061-0868
Facility: 144 DW Highway
Merrimack, NH 03054
Office +1 603.885.8137
Mobile +1 603.318.8056
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Phil Nutting
Sent: Thursday, April 16, 2009 9:11 AM
To: [log in to unmask]
Subject: Re: [TN] NPTH or PTH?
Li,
On our designs we typically use a non-plated through hole with an
unsupported pad for mounting holes regardless of what the mating
material might be. The unsupported pad acts like a flat washer under
the screw head. For a hole that might be part of the grounding scheme
we would use a plated through hole in that specific location.
I hope this helps.
Best regards,
Phil Nutting
Design for Manufacturing Engineer
Kaiser Systems, Inc.
126 Sohier Road
Beverly, MA 01915
voice: 978-922-9300 x1310
fax: 978-922-8374
e-mail: [log in to unmask]
www.kaisersystems.com
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of ??
Sent: Thursday, April 16, 2009 5:08 AM
To: [log in to unmask]
Subject: [TN] NPTH or PTH?
Dear all,
For the PCB assemble requirement, we always need NPTH or PHT holes to
have screws fasten it on the related structure. Here is the quetion,
when should we select NPTH holes or PHT holes?
For a meatal structure, a PHT hole maybe the best choice. For a plastic
structure, a NPTH hole may be used, why?
B.R.
Li Yi
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