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 > > > > > >