REPLY: Kitty,
Book on clearances for Agencies.....
We have had significant interface with the agencies listed
below, so I will attempt to outline for you. If you need
more specific info please send, or call to
[log in to unmask], or 303-790-4445 x5216.
VDE/CE requires tighter clearance specifications based upon
Voltages. All Primary to Primary clearances between traces
s/b 3mm (.120")[i.e. neutral to common to hot]. This
clearance holds up until you go thru a xformer, or bridge
type device, and cut your voltages to DC voltage. Keep in
mind all parts of the component body when planning
clearances-NOT just the traces/pads. We have been killed
several times by heatsink hardware-to-chassis violations
of < 6mm even when we took so much time with the PCB
clearances.
Also... If you have FlyBack voltages that increase in an
Xformer, there may even be greater spacing requirments for
those higher voltage traces.
Primary to secondary seperation requires 6mm
(.240")[i.e.neutral to digital signal trace in secondary].
Plan on compressing all AC into one area that you can
surround with a 6mm keep-out area, This would also include
internal planes, better to completely clear out any internal
copper if your design is M/Layer.
UL/CSA clearances are less rigid, but we have always planned
on following 3mm wherever possible just to be safe.
RADIAL COMPONENTS
=================
Added note....
When we have come across problems getting A.I. rules
from our overseas factories (common freakin' problem!), we
have requested the machinery brands, and actually called the
machinery reps to get copies of the A.I. rules that should
be followed.
There are very specific tooling requirements for all A.I.
machines as well as comp-to-comp spacing.
We actually incorporated these clearances into our libraries
to speed up future designs, and it has been well worth the
time to edit the lib files.
Keep in mind also that you have Clinched leads underneath
the components that can cause shorts with opposing clinched
leads on the bottom side of the PWA. Machines can be set-up
for different types of clinching options.
/
O
top view of typical 5mm radial device
O with 30deg. lead clinch angle.
/ /....problem
O area-will gather solder, and short!
O
/
hope this helps.
Les.
Hi to all!
This is a great place to get excellent information. I need some
info ASAP. I'm working on a board that is going to be manufactured
over-seas and can't get this information from that manufacturer. I
have some good guidelines for auto-inserting axial components and
DIPs, but I need to know the spacing requirements for radial
components (caps, transistors, 1/4W & 2W resistors that are stood
up). Can anyone help me out?
This board also has to meet UL approval per UL/CSA/CE/VDE for
250VAC. I am using 100mil trace widths with 100mil air gaps
minimum, sound good to you?
Hope you don't mind all my questions. More than that, I hope you
don't mind answering all my questions because I'm sure I'll be
asking alot more. That's what we're here for, right?
Thank You again!
Kitty
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