Have to agree with Tom, on FR4 clean cut is not a simple thing.
Which is why i emphasized the shape of cutting edge.
(check your paper binder hole puncher , works similarly)
We did the ovals on PS boards, high volume,
mainly for holding of large items which we did not want to strap,
straight in line wave, test, out .
I remember we did go through a selection of higher resin laminates,
to facilitate the cleaner cut, even than it obviously was nothing
crash hot smooth, however sufficient for the mechanical purpose,
without major outgassing dramas.
As you can imagine, the >mechanical< coarse barrel grip we actually
validated as being superior to smooth hole preferable for currents .
This is horses for courses design for a mass fabrication,
consumer products are actually challenging as well,
just different ways (cost).
Those days it was SE Degussa, i think, than mainland CH
Nowadays i have a good HK fellow who could repeat it in mainland fabs
at a cheap price with reasonable quality,
as long as you store the boards vacuumed,
which is a norm nowadays anyhow, i think .
Let me know if yo serious, get yo in touch with the fab,
but you have to be prepared to work with them .
As Bev said once, you can have good results with SEA fabs.
But Buddhist frame of mind helps to eventuate it.
As far as modern high volume boards,
i still keep a decade old Siemens CEM board ,
Double Sided copper ALL punched
and dispenser filled silver polymer (1/64)vias.
That was from days when i contemplated rock bottom $ fast radicals,
as this DS punch, all dispensed silver, p&p and UV cure tunnel .
But as Inge's finding now as well the adhesion character,
performance and variability's never reached even average quality solder.
However the via "cork" does have some merit as it is flexible.
To punch even DS FR4 on larger holes is not that much drama,
with well designed carbide dies,
however as you know below1/8 it starts to be difficult to relate to press.
Lord wouldn't forgive yo DS FR1,
perhaps superfreezed chock cookies can be punched clean,
never tried that (have to stop somewhere).
In the kiss terms , keep in mind WHAT you design for,
if without fill, with solder fill, with wire/tab reinforcement,
coarse, smooth, let it all work for you
cu Tom paul
-----Original Message-----
From: Tom Martin [mailto:[log in to unmask]]
Sent: Tuesday, 20 June 2000 7:44
To: [log in to unmask]
Subject: Re: [TN] oval pin into oval hole
Phil,
It's not the hole shape that is a problem, it's that the nature of a
punched
hole does not lend itself to plating. If someone devised a cost effective
method of plating thru holes on say CEM-3 or [Lord forgive me] FR-1
double-sided PUNCHED PCBs then people who design PCBs for
high-volume consumer electronics could spend evenings with
their families instead of pulling their hair out trying to get single-sided
PCBs and wire jumpers to approximate what a double-sided plated-thru
board could accomplish with only moderate difficulty.
Tom
Phil Nutting <[log in to unmask]> on 06/19/2000 05:16:03 PM
To: "'TechNet E-Mail Forum.'" <[log in to unmask]>, Tom
Martin/TVCOM-Knoxville Design Center
cc:
Subject: RE: [TN] oval pin into oval hole
Tom,
The process of plating a hole does not care about the shape. The hole can
be round, square, triangular, elliptical or a slot. It is a liquid process
that is going to "stick" to whatever surface is presented. Any fab house
should be able to plate any given hole.
We regularly have slots which are being plated.
Regards,
Phil Nutting
Manufacturing Engineer
Kaiser Systems, Inc.
-----Original Message-----
From: Tom Martin [mailto:[log in to unmask]]
Sent: Monday, June 19, 2000 4:49 PM
To: [log in to unmask]
Subject: Re: [TN] oval pin into oval hole
Just curious Paul,
Do you have access to PCB fabricators who can
plate punched slots and holes? I heard of
this being done on one occasion but would
be pleasantly amazed to find out there is a fab
house who's figured out how to do this on a regular
basis. Any info would be appreciated.
Thanks,
Tom Martin
Date: Mon, 19 Jun 2000 08:32:40 +1000
From: Paul Klasek <[log in to unmask]>
Subject: Re: oval pin into oval hole
MIME-Version: 1.0
Content-Type: text/plain; charset="iso-8859-1"
-----Original Message-----
Or a die punch , with large volumes routing is rather slow and expensive,
also the die can solve more intricate openings .
Relatively easy to keep horizontal concave ground carbide tips sharp .
paul
-----Original Message-----
From: Phil Nutting [mailto:[log in to unmask]]
Sent: Saturday, 17 June 2000 4:57
To: [log in to unmask]
Subject: Re: [TN] oval pin into oval hole
Richard,
We have several boards that we had to design plated through slots for
capacitors that either had large rectangular tabs or multiple wires going
to
the same hole. We used the same clearance rules that we normally would for
standard round holes. Depending on your board vendor these slots might be
created by drilling a series of holes or by routing.
Hope this helps,
Phil Nutting
Manufacturing Engineer
Kaiser Systems, Inc.
-----Original Message-----
From: Richard Hawkins [mailto:[log in to unmask]]
Sent: Friday, June 16, 2000 2:15 PM
To: [log in to unmask]
Subject: [TN] oval pin into oval hole
Hello all,
I am having trouble finding design specs for an oval component lead going
into an oval hole. The component is an indictor that is about 25mm in
diameter and the lead is made by soldering two 16ga wires together. The
shape of the lead is more like a rectangle with a full radius at the short
sides than an oval and the hole in the pcb is the same shape.
My task is to evaluate a design, that is already in production, to see if
it
should be changed and make recommendations if so. However, I have not been
able to find anything in my IPC manuals that approaches this situation.
My question then, is what guidelines for layout should I use?
Any help will be appreciated.
Richard Hawkins
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