Hi Mark,
        on the Nickel/Gold I made a couple of assumptions. It is Nickel and
Gold, not some fancy alloy and the thickness probably is in error. He is
probably including his final copper plate in with the Nickel/Gold
measurement as he doesn't list anything other then the initial 0.5oz foil
for the external layer.

Sincerely,
Brad Velander.

Lead PCB Designer
Norsat International Inc.
Microwave Products
Tel   (604) 292-9089 (direct line)
Fax  (604) 292-9010
email: [EMAIL PROTECTED]
http://www.norsat.com

See us at Booth S8155 at NAB 2002 in Las Vegas April 8 - 11.


> -----Original Message-----
> From: Mark E Witherite [mailto:[EMAIL PROTECTED]]
> Sent: Thursday, April 04, 2002 6:38 AM
> To: Protel EDA Forum
> Subject: Re: [PEDA] WANTED: PCB Expert (Off Topic)
> 
> 
> Hi,
> I did the math last night on the CTE differences.  When I saw 
> the thick 
> nickel plating (5 times the mil STD 275 minimum (.2mils)),  
> it looked like 
> a bimetal element to me.  But for a 10 inch length and a 100 degree C 
> change in temperature, the copper's final length was 10.017 
> inches and the 
> nickel was 10.0133 inches.   The 4 mill difference doesn't 
> appear to seem 
> to be a factor.  I would have to dig out the text books to 
> determine how 
> much bow it would cause and I don't have time for that.  
> Anyone know why 
> you would use such a think nickle plating?
> Cheers
> Mark

> > > -----Original Message-----
> > > From: H. Selfridge [mailto:[EMAIL PROTECTED]]
> > > Sent: Wednesday, April 03, 2002 13:24
> > > To: Protel EDA Forum
> > > Subject: Re: [PEDA] WANTED: PCB Expert (Off Topic)
> > >
> > >
<<<SNIP>>>
> > >
> > > At 04:52 PM 4/3/02 +0100, you wrote:
> > > >Many thanks,
> > > >
> > > >Details are as follows:
> > > >
> > > >6 Layer 1.6 FR4
> > > >8" x 10" Board
> > > >
> > > >PCB support is a wasted rectangle 10mm wide along all edges,
> > > supporting PCB
> > > >at 2 or 3 points along each edge.  (First observation is
> > > that this should
> > > >have copper layers)
> > > >
> > > >Layer stack up is two cores + two foils (sizes rounded to 1
> > > decimal place)
> > > >
> > > >R/P     Layer   Type                    thou
> > > >-       -       Resist          0.4
> > > >R       1       Ni/Au 0.5oz     1.1
> > > >R       1       Foil 0.5oz              0.7
> > > >-       -       Prepreg 7630    7.0
> > > >P       2       1oz Copper              1.4
> > > >-       -       Core                    15.0
> > > >R       3       1oz Copper              1.4
> > > >-       -       Prepreg 1080    5.0
> > > >-       -       Prepreg 1080    5.0
> > > >R       4       1oz Copper              1.4
> > > >-       -       Core                    15.0
> > > >P       5       1oz Copper              1.4
> > > >-       -       Prepreg 7630    7.0
> > > >R       6       Foil 0.5oz              0.7
> > > >R       6       Ni/Au 0.5oz             1.1
> > > >-       -       Resist          0.4
> > > >---------------------------------
> > > >Total                           64 = 1.625mm
> > > >

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