Ramakrishnan, Paul, Technetters...IPC-810, Guidelines for High Volume Microsection, is a document I have looked at with some care a few times. It was published in 1993, and not revised since.
A Buehler training representative spent 1.5 days with us in 2009, and his polishing instructions were to use 3-micron diamond with a Texmet low-nap cloth, for 1 minute at 5 pounds per mount, followed by 0.05-micron alumina slurry in microcloth high-nap cloth for 45 seconds at the same force per mount.
For some time I have wondered if it would be better to use 1-micron diamond on the Texmet cloth for final polish.
I notice 810, referring to high-nap cloth, states 'A run time over 1 minute will cause serious problems with copper smear and rounding. Beware of these cloths.' In 810, there is also the statement, referring initial polish, 'The pressure setting is much lower than grind (approximately 0.07 - 0.14 kg/cm^2 [1-2 psi])'. Our instructions were to use the same 5 pounds per mount for grinding and polishing.
Having recently, and perhaps belatedly, read IPC-TR-486, I have to wonder about the true value of performing all these microsections.
I hope the above is worth at least $0.02. Louis Hart
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Ramakrishnan Saravanan
Sent: Wednesday, December 26, 2012 3:39 AM
To: [log in to unmask]
Subject: Re: [TN] MICRO ETCH
Dear Mr Reid,
Thank you for the reply. My understanding is if we polish too much , the fine copper smear may fill the separation and it will be very difficult to remove using microetch.
What is the optimum level of polishing, whether we have to go down to 0.03 microns or can we stop it 1 micron polish before microetch.
regards,
R.Saravanan
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