As I wrote earlier, this is a failure of the IPC. Why would any maker of
X-ray inspection equipment accept responsibility for limiting dose to some
undefined level for silicon, when they also make equipment for inspecting
aluminum castings, plastics, ceramics, gold all of which absorb different
energy level emissions. Why would any device manufacturer limit their
market by publishing dose limits when their competitors do not.
If the IPC accepts responsibility for this problem, then a committee of
stake holders can Analyse the problem, Define the problem, Ideate solutions
for the problem, Implement and evaluate and revise.
On Fri, Sep 6, 2019 at 7:27 PM <[log in to unmask]> wrote:
> Right and my understanding is that the soft x-rays are more harmful than
> the hard ones, so I've heard.
> Bev
>
> -----Original Message-----
> From: TechNet <[log in to unmask]> On Behalf Of Guy Ramsey
> Sent: September 6, 2019 6:26 PM
> To: [log in to unmask]
> Subject: Re: [TN] XRAY inspection of SMT
>
> The filter absorbs low energy that does nothing for the image, but would
> otherwise be absorbed by your product.
>
> On Fri, Sep 6, 2019 at 5:22 PM Wayne Thayer <[log in to unmask]>
> wrote:
>
> > What's the difference between a filter and just dropping the power?
> >
> > On Fri, Sep 6, 2019 at 12:39 PM Bev Christian
> > <[log in to unmask]
> > >
> > wrote:
> >
> > > TechNetters,
> > > Guy nailed it when he mentioned "Zn filter". We (BlackBerry) just
> > > used commercial grade Al foil and that seemed to do the trick. With
> > > regards
> > to
> > > 2D/3D, I would think if your 3D machine is fast enough this
> > > shouldn't be
> > a
> > > problem (with filter). Comments?
> > >
> > > Regards,
> > > Bev
> > >
> > > -----Original Message-----
> > > From: TechNet <[log in to unmask]> On Behalf Of Guy Ramsey
> > > Sent: Friday, September 6, 2019 3:24 PM
> > > To: [log in to unmask]
> > > Subject: Re: [TN] XRAY inspection of SMT
> > >
> > > We had a great discussion on this topic last year. In response we
> > > purchased a gross of little dosimeters from Landauer, and
> > > characterized
> > our
> > > 3D AXI.
> > > The results were truly horrifying.
> > > We shared our results with the manufacturer. Characterized their new
> > > machine and decided 3D AXI was not for us. We traded the machine for
> > > two upgraded AOI machines.
> > > Then we evaluated x-ray equipment with new knowledge. Added a zinc
> > > filter and now do 2D x-ray at a safe and reasonable dose.
> > >
> > > On Fri, Sep 6, 2019 at 3:07 PM Wayne Thayer <[log in to unmask]>
> > > wrote:
> > >
> > > > I thought you guys would get a kick out of something Analog
> > > > Devices just sent me when asked about a voltage reference chip
> > > > apparently damaged by XRAY inspection:
> > > >
> > > > "Given all the variables that can affect device performance,
> > > > Analog Devices, Inc. does not recommend subjecting non-radiation
> > > > hardened or tolerant devices to radiation exposure beyond normal
> > > > background
> > > radiation.
> > > > "
> > > >
> > > >
> > > > Brilliant, huh? Don't XRAY ANY ADI parts unless they are the tiny
> > > > subset of the radiation hardened line!
> > > >
> > > > My expectation is that they would give a dosage range. Silly me....
> > > >
> > > > Wayne Thayer
> > > >
> > >
> >
>
>
|
