Richard- Have you tried reaching tray manufacturers suchas Peak, Summit,
Nepenthe or Sumitomo? How about the assembly & test houses for the
semiconductor industry (Amkor, ASE, OSE, ASAT, ChipPac, etc.)?

Generally speaking all parts are oriented in the tray s the same way,
because the trays have to be indexed by the component test house. That is,
pin one of the device will always be in the same position across the tray,
and all trays in a bundles will be oriented the same, and all bundles in a
box will be oriented the same and finally, all boxes in a crate may NOT be
oriented the same. The likeness in orientation is caused by computer vision
machine systems; the crating is all done by hand, so humans screw that up.

Next the trays themselves. They is a tendency, especially among higher pin
counts (200+) devices to "cross-use" trays. Unless you want coplanarity
issues with your fine pitch devices, don't allow this. Even though a fine
pitch 204 pin tray will accept a FP 176 pin device , the problem comes with
the support dam under the legs of the device as they sit in the trays.

I would also recommend that you only allow usage of trays that can withstand
130C temperatures without warpage. In the event that you receive a tray with
the barrier bag violated, you will want to perform bakeout. This is best
done in the trays to avoid excessive component handling.

Finally, be suspicious if you recive parts in trays other than black in
color. Virtually every semiconductor assembly house uses 4 colors: black,
blue red & green. The red trays are used inside the assembly plant to denote
faulty devices; the green denote engineering standards, the blue indicate
untested devices. (Some houses may vary this slightly, but you get the gist
of it...). They ship exclusively only in black trays (unless you have made a
bonehead art deco decision & asked them to do otherwise.).

Please note that everything I've told you is from first hand experience-
there is no industry standard, only common industry 'best practices'.

If you have concerns about whether or not the part is coming to you in the
proper tray- try this experiment- take a tray of devices and bake it for 4
hours at 125C. Then send it out for RVSI scanning. RVSI scans the corner
pins of the device for coplanarity. You need to ask the RVSI facility to
scan it in your tray. They can tell you if the leads are in compliance with
JEDEC coplanarity requirements, and if the tray has warped beyond the JEDEC
requirements.

Hope this helps...

>  Bill Davis, Ph.D
>       MS&PF
  408-273-2921
[log in to unmask]



-----Original Message-----
From: Hamilton, Richard CLE 4454 [mailto:[log in to unmask]]
Sent: Thursday, November 04, 1999 4:57 PM
To: [log in to unmask]
Subject: Re: [TN] QFP Tray Packaging


Hey Steve,

Yes I did go there and look, although I did not see what I was looking for.
Maybe I just did not go far enough. I did not see anything listed for tray
packaging and when I looked at QFP all I saw was for component packaging. I
guess I better go back and not be so short with the eyes!

Thank you for the comment on the vendor supply of orientation. That makes it
sound to me like there may not be a standard for what I want to lay claim
to! Oh Well! I am gonna try again though!

Richard Hamilton
Clemar Mfg. / Rain Bird
[log in to unmask]

> Hey Richard!
>
> Did you go through that Topline page that I sent ya'? It's gotta lot of
> the
> stuff that you're looking for...standard JEDEC tray sizes, standard reel
> sizes, etc., ect...I knew what you were looking for...
>
> But if that isn't what you need, go to:
> http://www.jedec.org/download/default.htm
> that's a page where all there's all kinds of EIA/JEDEC industry standards
> that you can download for free...you'll need to go through all the
> standards
> to look for the ones you need...I'm not gonna do all the work for
> ya'...hehehe.
>
> But as far as orientation of pin one, you'll need to take what you get
> from
> your vendors, I don't think everybody is working together that close
> yet...just as long as they're all the same from a particular vendor is
> about
> all you can expect.
>
> Happy flappin'...hehehe
>
> -Steve Gregory-
>

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