Leo,
We use a machine called "Afta-Score" made by a company called
Radoll Designs to finish the depanalization process. Our boards are
scored by the board shop approx 1/3, or less, on each side. This
leaves enough material that the boards are not too weak.
Components can be mounted fairly close to the edges, but I don't
have the keep away info at hand.
Radoll Designs, Inc.
James Maddox, VP
309 Baybrook
P. O. Box 125
Thomas ville, GA 31799-0125
912/228-0200 Voice
912/226-4150 FAX
Once we are finished processing the boards, they are run thru the
Afta-Score and can then be broken apart very easily by hand.
Hope this helps.
Charlie Barker [log in to unmask] [log in to unmask]
On 04/25/96 05:17:47 PM Gita Khadem wrote:
There is nothing wrong with scoring and a proper panelization and
scoring/routing can result in major PWB cost savings.
You just have to determine in advance how the boards will be
depanalized in production and design in the required criteria at the
PWB level up front.
If production plans on using equipment to depanel (punch, V-blade,
etc.), then you need to know the component placement keep outs
required around the edges of the board to clear the blades as well as
component height restriction,etc.
If boards are broken by hand, then DO NOT place any component close to
the edge since solder joints will get damaged. As Gary has indicated
below, the board dimension is not appropriate for breaking by hand and
I don't even know if there is enough room on the board (1/2" X 10") to
move components away from the edges for a punch equipment.
[log in to unmask]
Leo,
There are equipment out there (Pizza cutter!!) designed to depanel V-grooved
board. The V-blade used in those equipment will minimize bending stress
inflicted on the PCB to minimum.
(BTW,try to reduce the groove web to 0.015" if possible)
Yuen
----------
From: TechNet-request
To: Leo Reynolds
Cc: Technet
Subject: Re: ASSY: Depanelization of SMT Board Assys
Date: Thursday, April 25, 1996 8:37AM
Leo;
We experienced similar problems with a board the same dimensions. When we
investigated the excising methodology we were astonished to find that the
customer was attempting to break the boards away, by hand! Boards with
unsual aspect ratios, must be broken ustilizing a fixture that applys
uniform pressure at the break point. This should reduce the forces that get
transmitted into the board and the componet solder joints.
Regards,
Gary Ferrari
Tech Circuits
At 04:33 PM 4/24/96 -0500, Leo Reynolds wrote:
>We are a contract manufacturer and are currently having trouble with a 1
>1/2" X 10" SMT board assy. It was designed in a panel of 6, scored for
>eventual break apart and the original scoring left .018" of material in the
>groove. When we started to break them apart we found we were cracking some
>of the SMT caps. We've since instructed the PCB mfgr to go to a more
>standard .012" per one engineers recmmendation, but don't have samples yet
>to try. One of our process engineers attending Nepcon had several
engineers
>tell him that SMT boards shouldn't be scored at all.
>
>We are trying to determine the best course of action to recommend to our
>customer. The customers design engineer felt we shouldn't have had a
>problem with the original .018" groove so we may have to put together a
very
>god case for changing to routing or anyuthing else.
>
>Anyone have any recommendations?
>
>Thanks in advance for your consideration.
>
>Leo Reynolds
>
>
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