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From:
Riccardo Inverardi <[log in to unmask]>
Reply To:
TechNet E-Mail Forum <[log in to unmask]>, Riccardo Inverardi <[log in to unmask]>
Date:
Wed, 18 Apr 2018 09:51:28 +0200
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Thank you for your input.
Checking for ESD-safeness was something I have to admit I didn't had in
mind. As you said - I took somehow for granted that an equipment like that
should be ESD-safe!

The magnifying glasses that Joyce suggested seem not to have enough
magnification power: since the main work would be a final call, I would
prefer to give my operators a tool capable of magnifying in the range of 10x
- 40x or at least 10x - 20x. Our AOI is inline after reflow, so no
inspection of conformal coating, nor THT is carried on in the stations we
are talking about. To check polarities or markings, as well as chip solder
joints is easily done via the AOI images. What the operators usually have
problems with, are fine pitch gullwings, which are sometimes difficult to
reliably inspect in a 2D AOI: front meniscus not always present (nor
required BTW) and pads with too little space for side meniscus to form.

I'm open for other alternative suggestions: the operators will soon be
certified as CIS for the 610 (so excited about my first classes as CIT) and
I don't want to be unprepared already on chapter 1.10 :-)

It seems that the only solution may be an off-line inspection station, with
proper microscope, ESD protection and why not, a solder iron for touch up.

Riccardo Inverardi
INTEA ENGINEERING


-----Messaggio originale-----
Da: Stadem, Richard D [mailto:[log in to unmask]] 
Inviato: marted́ 17 aprile 2018 15:39
A: TechNet E-Mail Forum <[log in to unmask]>; Riccardo Inverardi
<[log in to unmask]>
Oggetto: RE: [TN] Handy Magnifiers anyone?

Consider also the required magnification. While Joyce's suggestion is a good
one for the purpose of screening false calls, the magnification for
different features on a given circuit board must fall within IPC-A-610
and/or J-STD-001 requirements. This is typically 20x for solder joints, less
for most other applications such as checking polarity, epoxy
staking/bonding, etc. (naked eye, 4-10X for referee purposes). If a final
call on an AOI defect is going to be determined by the referee tool, it
better have the correct magnification capability for what is being
inspected. Things like particulate matter, etc, are also naked eye, 4-10x
referee, and so on and so forth. If the inspector/operator is not trained to
use the correct magnification for what he/she is looking at, you will have
all kinds of issues and non-value-added rework and touchup costs packed into
your process. Not only you need to keep the inspection tool well calibrated,
you also need to keep the Inspector's eyeballs well calibrated as well! They
all have to be on the same page.

-----Original Message-----
From: Stadem, Richard D 
Sent: Tuesday, April 17, 2018 8:27 AM
To: [log in to unmask]; 'Riccardo Inverardi'
Subject: RE: [TN] Handy Magnifiers anyone?

You may wish to check the Mantis for ESD. The one I had experience with was
a huge ESD generator (tribo-charged to greater than 10,000 volts using a
calibrated field meter). No matter what you select, just be sure it is
ESD-safe. Every single board is going to go by under your inspection tool.
Not having an ESD-safe tool is not very smart. 
You would think the manufacturers of inspection systems that are targeted
for electronics use would make sure they are ESD-safe. Guess what? Most are
not!

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Riccardo Inverardi
Sent: Tuesday, April 17, 2018 4:25 AM
To: [log in to unmask]
Subject: [TN] Handy Magnifiers anyone?

Greetings to all TechNetters, I am facing a problem and I hope that the
great experience of the forum can help me.

 

I have to provide our AOI operators with an adequate magnification and
illumination aid to inspect those features that a 2D AOI cannot reliably
inspect and/or to discriminate false calls from real defects.

We have evaluated different magnification aids: from digital magnifiers, to
binocular microscopes. The absolutely best option is a stereo microscope
such as Vision Engineering's Mantis line: depth perception is maintained and
once the focus has been set, it's easy to switch from focusing on the PC
screen and inspecting the board.

Disadvantages are high cost, but the worst is that they are cumbersome.

On the other hand, tabletop magnifiers are cheap, have good illumination and
they are really handy. It's a pity that they usually are too cheap and most
of all, it seems that no one makes them with adequate magnifying power.

 

Currently, our operators have to work ideally in a 1.5 square meters' area
(actually, they are not trapped in: it's just a "designated area").

 

Any suggestion, past experience and lessons learned that you can share will
be highly appreciated.

 

Have a nice day,

Riccardo Inverardi
AOI Programmer | IPC/J-STD-001 + IPC-A-610 Certified IPC Trainer


 <http://www.inteaengineering.it/> INTEA ENGINEERING via Chiusure 20 Sale
Marasino (BS) T +39 030 9824406 | F +39 030 9824407

 

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