Hi Pradeep,
I think maybe it is better to design your rigid flex with reinforcing tabs
and breakaways to keep everything rigid so that you can build it, and
relieve the flex from the edges and place tabs and mouse-bites at strategic
locations. Below is a photo of a rigid-flex assembly I was involved in
building some time ago that illustrates what I mean. The whole thing was
de-panelized and folded up into a cube more or less:
http://stevezeva.homestead.com/files/RigidFlexAssy.jpg
Steve
-----Original Message-----
From: Glidden, Kevin
Sent: Wednesday, January 16, 2013 12:03 PM
To: [log in to unmask]
Subject: Re: [TN] V scoring of Rigid flex PCB
Fully route the rigid portions, and leave small connecting tabs on only the
inner layer flex layers. Then you can simply use an xacto or other type
blade to separate the flex-rigid simply by cutting the flex tabs.
-----Original Message-----
From: Pradeep Menon [mailto:[log in to unmask]]
Sent: Wednesday, January 16, 2013 10:53 AM
To: [log in to unmask]
Subject: Re: [TN] V scoring of Rigid flex PCB
Thanks for the inputs. But my query is more specific on Rigid flex V
scoring. We do V scoring at our end as well.
The issue is with Rigid flex ( or flex rigid) PCBs wherein there will be
flex polyimide layers ( mostly at the center, with the rigid portion
towards the outer layers. For a 1.6mm thick rigid PCB, we usually do a 0.6mm
depth V cut on either side which means there is a web of 0.4mm. This is
easily 'breakable' since it is rigid. But if we have a flex in the remaining
web portion, it is not breakable. Hence the doubt on any accepted practice
or method for Rigid flex V scoring.
Rgds
Pradeep
-----Original Message-----
From: Nutting, Phil [mailto:[log in to unmask]]
Sent: Wednesday, January 16, 2013 8:35 PM
To: TechNet E-Mail Forum; Pradeep Menon
Subject: RE: V scoring of Rigid flex PCB
Pradeep,
You will find several discussions on V-scoring in the Technet Archives.
V-scoring is discussed in IPC 2222.
The Internet has many locations that discuss it, for example:
http://www.pcbstandards.com/forums/showthread.php?t=2261
To separate the boards at the V-score typically a sharp wheeled device (like
a pizza cutter) is drawn over the V-score and does a very nice job of
cutting the boards apart. Bending the boards so they break at the v-score
works but is a VERY BAD PRACTICE as it puts large stress on components near
the edges which possibly causes failures of the circuit with broken
components or cracked etches.
See http://www.cab.de/en/electronics/pcb-separators/ for pcb separators.
Good luck,
Phil Nutting
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Pradeep Menon
Sent: Wednesday, January 16, 2013 8:19 AM
To: [log in to unmask]
Subject: [TN] V scoring of Rigid flex PCB
Importance: High
Sir/Madam,
We have a customer who has asked for v scoring of rigid flex pcb. We are
wondering how the PCB will be separated later, once we supply to them. Our
customer has a drawing which calls for it, but they are also not very clear
on this. We wanted to know whether there is a separate IPC standard or
guidelines for V-scoring of rigid flex PCBs.
Tgds
Pradeep
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