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May 2000

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Subject:
From:
Gabriela Bogdan <[log in to unmask]>
Reply To:
TechNet E-Mail Forum.
Date:
Thu, 1 Jun 2000 07:20:24 +0300
Content-Type:
text/plain
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text/plain (171 lines)
Rick,
I second your opinion. We use the equipment also for component failure analysis. It is
the first step before decapsulation,and it saves  a lot of time.
But, as many others explained, it is only a tool, and must be in the hands of skilled
people. When Michelangelo got the rock, he imagined David inside.
Thanks,
Gaby

"Howieson, Rick" wrote:

> Jerry,
> Thanks for your FIRST sentence, opinion. We use x-ray and as far as
> troubleshooting and improving our process it has been one of the best
> investments made.
> Rick Howieson
> General Technology Corp.
>
> >-----Original Message-----
> >From:  Jerry Cupples [SMTP:[log in to unmask]]
> >Sent:  Tuesday, May 30, 2000 4:12 PM
> >To:    [log in to unmask]
> >Subject:       Re: [TN] To X-ray or Not to X-ray.
> >
> >At 02:53 PM 5/30/00 -0600, you wrote:
> >
> >>Help,
> >>
> >>My company is asking for information leading to the possible purchase of an
> >>X-ray machine for BGA s.
> >>
> >>We are placing some with metal tops such as the ALTERA.  ANY info on who,
> >>what, where, etc. etc. etc.
> >>
> >>Would be kindly appreciated.
> >
> >I have an opinion here, and it's just an opinion...
> >
> >Buying an X-Ray machine "for BGA's" is pretty common, as of course you can't
> >"see" the joints much otherwise.
> >
> >But you wouldn't buy an X-Ray machine just to check your lungs every 6
> >months, would you? Not even if you were doing it for every employee, you
> >wouldn't.
> >
> >My brother is a radiologist. He can look at images which look like clouds,
> >and pick out the "Roentgen signs" that indicate disease and abnormalities.
> >When I look at them, they look like clouds. It took him years of internship
> >and residency to develop the skill analyze the images, plus a photographic
> >knowledge of human anatomy achieved along the way. He needs to know what
> >every section of a body SHOULD look like, and indicators for many
> >abnormalities in males, females, adults, juveniles.
> >
> >If you do buy one, you should plan to dedicate a technician who will learn
> >how to operate the equipment, process the images, and interpret what is found
> >- and the time and cost of this manpower is probably greater than the cost of
> >the equipment. You can expect it to be a long process to get much useful
> >information. There are many types of packages, and they are mounted on
> >different boards with different pads. This will change every six months or so
> >with some regularity.
> >
> >Some  people think the process of interpreting the image ought to be simple,
> >like looking at the x-ray of a broken arm, and seeing the crack, and saying,
> >"yes, it's broken". The reality is that you see cloudy images and have to
> >adjust the contrast and use a lot of your training and experience to
> >determine what the image means.
> >
> >Having an X-Ray machine just to find shorts on BGA's after soldering is
> >overkill. What you may want is the ability to make judgements about the
> >amount of solder, the voids, and the wetting. This requires laminography,
> >sophisticated image processing, a trained technician, and then you have
> >indications which can be used to make logical inferences, not necessarily
> >clear cut process measurements. (I've seen my brother arguing with other
> >radiologists about the meaning of images, and he wrote a chapter in one of
> >the medical texts...)Your mileage may vary, etc.
> >
> >
> >cheers,
> >
> >
> >Jerry Cupples
> >Interphase Corporation
> ><html>
> >At 02:53 PM 5/30/00 -0600, you wrote:<br>
> ><br>
> ><blockquote type=cite cite><font face="arial" size=2>Help, <br>
> ></font><br>
> ><font face="arial" size=2>My company is asking for information leading to
> >the possible purchase of an X-ray machine for BGA s.<br>
> ></font><br>
> ><font face="arial" size=2>We are placing some with metal tops such as the
> >ALTERA.&nbsp; ANY info on who, what, where, etc. etc. etc.<br>
> ></font><br>
> ><font face="arial" size=2>Would be kindly appreciated.<br>
> ></font></blockquote><font face="arial" size=2><br>
> ></font>I have an opinion here, and it's just an opinion...<br>
> ><br>
> >Buying an X-Ray machine &quot;for BGA's&quot; is pretty common, as of
> >course you can't &quot;see&quot; the joints much otherwise.<br>
> ><br>
> >But you wouldn't buy an X-Ray machine just to check your lungs every 6
> >months, would you? Not even if you were doing it for every employee, you
> >wouldn't.<br>
> ><br>
> >My brother is a radiologist. He can look at images which look like
> >clouds, and pick out the &quot;Roentgen signs&quot; that indicate disease
> >and abnormalities. When I look at them, they look like clouds. It took
> >him years of internship and residency to develop the skill analyze the
> >images, plus a photographic knowledge of human anatomy achieved along the
> >way. He needs to know what every section of a body SHOULD look like, and
> >indicators for many abnormalities in males, females, adults,
> >juveniles.<br>
> ><br>
> >If you do buy one, you should plan to dedicate a technician who will
> >learn how to operate the equipment, process the images, and interpret
> >what is found - and the time and cost of this manpower is probably
> >greater than the cost of the equipment. You can expect it to be a long
> >process to get much useful information. There are many types of packages,
> >and they are mounted on different boards with different pads. This will
> >change every six months or so with some regularity.<br>
> ><br>
> >Some&nbsp; people think the process of interpreting the image ought to be
> >simple, like looking at the x-ray of a broken arm, and seeing the crack,
> >and saying, &quot;yes, it's broken&quot;. The reality is that you see
> >cloudy images and have to adjust the contrast and use a lot of your
> >training and experience to determine what the image means.<br>
> ><br>
> >Having an X-Ray machine just to find shorts on BGA's after soldering is
> >overkill. What you may want is the ability to make judgements about the
> >amount of solder, the voids, and the wetting. This requires laminography,
> >sophisticated image processing, a trained technician, and then you have
> >indications which can be used to make logical inferences, not necessarily
> >clear cut process measurements. (I've seen my brother arguing with other
> >radiologists about the meaning of images, and he wrote a chapter in one
> >of the medical texts...)Your mileage may vary, etc.<br>
> ><br>
> ><br>
> >cheers,<br>
> ><br>
> ><br>
> >Jerry Cupples<br>
> >Interphase Corporation</html>
> >
>
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