Reading labels on small ICs
in [Design]
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From: Chuck Olson on 19 Dec 2009 11:48 "Chuck Olson" <chuckolson01(a)REMOVETHIScomcast.net> wrote in message news:hggqs7$tiq$1(a)aioe.org... > > "Harry D" <harryd(a)tdsystems.org> wrote in message > news:42987c77-ce23-4e80-adb8-0641bda7bebd(a)y10g2000prg.googlegroups.com... >> Gentlemen of this distingushed group, >> How do you read labels on small ICs such as the ThinSOT or DFN packs >> that are 2mm x 3mm? >> Ok, I have old eyes, soldering these pups is do able but finding >> pin#1 is impossible for me even using 7X eye loupe. I know JL will say >> it is no problem with his $3K Mantis and others are so rich that they >> hire a tech but I am not in that group. There's got to be an easier >> way, say <$300. >> Former member needs help; >> Harry D. > > Hi, Harry, > > I thought everyone who works in today's electronics had garnered for > himself at least one zoom stereo microscope. They usually go for about > $200 at flea markets here in Silicon Valley (San Jose, CA). On Ebay they > might be a little bit more. The new Celestron 44202 at $280 is in our > price range, but lacking the zoom feature is a terrible handicap. IMHO 20X > and 40X power levels are much too high for most electronics work - - I > find myself using 7X most of the time. Over the years, I've encountered > enough industrial salvage to populate every work bench I own with at least > one Bausch & Lomb Stereozoom 4, and more recently I had the good fortune > to spot an Olympus ZS4045 with a pair of Olympus GSWH10X/22 eyepieces and > a ringlight for $160. The view through that thing is breathtaking! Looking > through these instruments, if something is written, you'll be able to read > it. They open up whole new worlds of possibility in electronic and almost > any other area you can imagine. I find one almost indispensable for > removing a sliver! I'm sure I'm not telling you anything you don't already > know when I say, "If you can see it, you can do it". > > I just looked at Ebay - - don't buy one with 15X eyepieces - - 10X > eyepieces are what you want. It should be complete with a stand - - > there's a very nice 0.7X - 3X with 10X eyepieces on Ebay with a glass > platform on a high-base stand that provides bottom illumination, but you > probably won't use the bottom light much - - the stand will accommodate a > Kohler illuminator for top lighting or a ringlight and they don't cost a > whole lot. Don't buy a Stereozoom 6 - - in my experience field > illumination is poor so they are not worth the extra cost. > > Good luck to you, > > Chuck I apologize for a couple of errors - - the Olympus microscope was the SZ4045, and the intended illuminator is better described as a Nicholas illuminator rather than Kohler. There are also fiber optic and LED illuminators that are worth considering.
From: pimpom on 20 Dec 2009 15:05 Harry D wrote: > Gentlemen of this distingushed group, > How do you read labels on small ICs such as the ThinSOT or DFN packs > that are 2mm x 3mm? > Ok, I have old eyes, soldering these pups is do able but finding > pin#1 is impossible for me even using 7X eye loupe. I know JL will say > it is no problem with his $3K Mantis and others are so rich that they > hire a tech but I am not in that group. There's got to be an easier > way, say <$300. > Former member needs help; > Harry D. I use a lens salvaged from an old 16mm projector. http://img695.imageshack.us/img695/2571/16mmprojectorlens.jpg Pros: good magnification and excellent optical quality compared to a magnifying glass. Cons: Not hands-free - unless you rig up a holder.
From: Smitty Two on 21 Dec 2009 07:15 In article <42987c77-ce23-4e80-adb8-0641bda7bebd(a)y10g2000prg.googlegroups.com>, Harry D <harryd(a)tdsystems.org> wrote: > Gentlemen of this distingushed group, > How do you read labels on small ICs such as the ThinSOT or DFN packs > that are 2mm x 3mm? > Ok, I have old eyes, soldering these pups is do able but finding > pin#1 is impossible for me even using 7X eye loupe. I know JL will say > it is no problem with his $3K Mantis and others are so rich that they > hire a tech but I am not in that group. There's got to be an easier > way, say <$300. > Former member needs help; > Harry D. Used microscope from ebay or craigslist, or set your camcorder on macro and use the TV for a monitor. Older or non-functioning (i.e. non-recording) camcorders are dirt cheap. Put it on a stand above your work surface, throw plenty of light on the subject, and you can also do assembly with it. I bought a couple of used B & L Stereo Zoom microscopes on ebay about two years ago for about 300 each. But be careful if you go that route. One of them was "substantially not as advertised" and I entered into a formal dispute with the seller. (The Mantis, IME, is useless. It wobbles all over the place when you try to adjust it, making the autofocus do Elvis imitations. At least, the factory demo unit I worked with 20 years ago did. The floating arm mounting system was ill-suited to the magnification power. Perhaps they've improved.)
From: John Doe on 23 Dec 2009 04:38 Harry D <harryd(a)tdsystems.org> wrote: > Gentlemen of this distingushed group, How do you read labels on > small ICs such as the ThinSOT or DFN packs that are 2mm x 3mm? An inexpensive ~$50 digital microscope like a Carson Z-pix MM-640. Plugs into your USB port, no battery power. Has four bright LEDs. The object must be less than 1" away. The maximum viewing area is at least 1/2". There are other brands of digital microscopes, but that is what I have. I think it is perfect for what you are talking about (that is mostly what I have used it for). The viewing surface must be flat so that it can get close enough. The object should be clamped/stationary so that you can use your hands to position the microscope and focus it. You can see the image on your computer screen, and you just click the top button to take a picture that is automatically saved.
From: Don Klipstein on 23 Dec 2009 09:53
In article <00aa72dd$0$1493$c3e8da3(a)news.astraweb.com>, John Doe wrote: >Harry D <harryd(a)tdsystems.org> wrote: > >> Gentlemen of this distingushed group, How do you read labels on >> small ICs such as the ThinSOT or DFN packs that are 2mm x 3mm? > >An inexpensive ~$50 digital microscope like a Carson Z-pix MM-640. >Plugs into your USB port, no battery power. Has four bright LEDs. >The object must be less than 1" away. The maximum viewing area is >at least 1/2". > >There are other brands of digital microscopes, but that is what I >have. I think it is perfect for what you are talking about (that >is mostly what I have used it for). The viewing surface must be >flat so that it can get close enough. The object should be >clamped/stationary so that you can use your hands to position the >microscope and focus it. You can see the image on your computer >screen, and you just click the top button to take a picture that >is automatically saved. I have a couple other tools handy: 1. My Canon Powershot A640 digital camera can get ridiculously close to things, like half an inch. The frame can be filled with something half the size of a postage stamp. At 1 inch away, a 2x3 mm object should still show up well. 2. Since I do a fair amount of simple optical work for developing various LED lighting products, I have among things plenty of lenses handy. For example, several convex ones with focal length in the range of 3/4 inch to 1.75 inches as well as longer. I find ones with focal length in the 1-1.5 inch range very convenient for looking at the tinyest things. - Don Klipstein (don(a)misty.com) |