Thanks Bruce. May be I should try myself.
re,
ken patel
At 12:58 PM 5/12/98 -0400, you wrote:
> Ken,
>
> If you have access to some small grinding tools, i.e. a variable speed
> Dremel tool or better yet, cross-sectioning equipment, carefully grind
> down three of the four sides of the perimeter of the lid. If you know
> which end of the package the crystal is in, leave that edge alone;
> grind the other three. Once you just start to break through, use a new
> X-acto, with minimum penetration of the blade into the case, to pry
> and slice open the unit. Fold back the lid along the unground edge,
> and use it to hold the part. If you watch your grinding speed, and
> don't use water, you won't introduce any foreign matter into the
> package, or damage the crystal.
>
> Once you're inside, you can examine the crystal under a normal 30X
> microscope and check for cracks and chips in the crystal. Sometimes,
> the conductive epoxy used to cement them to the spring mounts, fills
> the mounts - making them solid, which makes the part very vulnerable
> to shock damage. Sometimes they're built just fine and as Tuan says
> below, they're just too roughly handled. I've also seen solder shorts,
> unsoldered pins, etc., which were manufacturing defects.
>
> This delidding technique works well; I've done it many times. Try it
> out first on a few parts that you don't care much about before going
> after one you want to seriously investigate. Careful of the sharp
> edges on the lid & package.
>
> Bruce Tostevin
> Benchmark Electronics
> Hudson, NH
>
>
>______________________________ Reply Separator
_________________________________
>Subject: Re: [TN] Crystals/Oscillators failure
>Author: Tuan300859 <[log in to unmask]> at 0UTG0ING
>Date: 5/11/98 6:30 PM
>
>
>Ken,
>
>I have experienced this failure before. The root cause is definitely due to
>handling. The crystal/oscillator is a fragile component. It can get damaged
>even in tube. The crystal will crack when drop from a distance of 5 inches
>to a hard surface. My recommendation is to transport these crystal parts in
>a foam pads , not in tube and definitely not in bag. And lastly, all
>operators from shipping, stockroom, hand load, and PC need to be awared of
>handling issue of the crystals/oscillators.
>
>I hope this helps!
>
>Tuan
>
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______________________________________________________
Ken Patel Phone: (408) 490-6804
1708 McCarthy Blvd. Fax: (408) 490-6859
Milpitas, CA 95035 Beeper: (888) 769-1808
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