SO8N package - pin 1?

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Hi all,

 

I've got some 8 pin SOIC package chips in a tape. Pin 1 is not marked in any way on the chip!  There is no notch on the pin 1 end, no dot molded into the part, no asymmetry to the package, nothing to indicate where pin 1 is!

 

I wonder if there is a "standard" which defines WHERE pin 1 is in an SOIC tape? I Googled everywhere, found lots of SOIC tape info, but nothing that seems to indicate any pin location standard.

 

And, of course the datasheet for the chip does not indicate pin 1 either. The datasheet shows a line of some sort molded into the package, but there is no line on the actual chip.

 

Please see attached images.

 

(click thumbs for full size)

JPEG image

 

JPEG image

 

JPEG image

 

Any info will be appreciated!

This topic has a solution.

Gentlemen may prefer Blondes, but Real Men prefer Redheads!

Last Edited: Wed. Mar 11, 2020 - 12:00 AM
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There’s a clear bevel on the left hand side of the package.

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Letting the smoke out since 1978

 

 

 

 

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Kartman wrote:
There’s a clear bevel on the left hand side of the package.
digitalDan wrote:

 

WOW you're right!

 

I looked at the chip from the top and could see no difference. When I looked end-on, it was plainly visible! It's sort of like this (the vertical "pipe" symbol representing the less sloped side):

 

 ______

/      |

-------

 

(how did I not see it before?)

 

Thanks!

 

Gentlemen may prefer Blondes, but Real Men prefer Redheads!

Last Edited: Wed. Mar 11, 2020 - 12:01 AM
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And clearly documented on the drawing.

 

Ross McKenzie ValuSoft Melbourne Australia

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As they say, the bevel is in the details.

When in the dark remember-the future looks brighter than ever.   I look forward to being able to predict the future!

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avrcandies wrote:

As they say, the bevel is in the details.

 

10/10!

 

- S

 

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Also, the chip datasheet often includes a spec for the packaging (strip, boxes etc, not the chip itself) which should include things like where pin one is, so it can be fed into pnp machines.

 

Neil

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barnacle wrote:
Also, the chip datasheet often includes a spec for the packaging:

No doubt that's where the OP's diagram came from ?

 

which should include things like where pin one is

and, as Ross pointed out, it does:

 

 

 

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I'm more "old school" and would simply have gone on the principle that chips tend to be:

 

This went a bit Pete Tong when you posted the photo the wrong way up:

 

 

if you turned it the right way up so the ST logo was clearly visible then it seems to conform to my simplistic, old school pattern too....

 

 

(this cunning plan goes to hell in a handcart on the occasion that they load the chips into the silk screening machine the "wrong way up" ! ;-)

 

Last Edited: Wed. Mar 11, 2020 - 02:13 PM
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@AWNeil - yes, that's the *package* drawings; I had in mind the *packing* drawings... which I've certainly seen on datasheets before but a random ST processor datasheet I just looked at didn't have...

 

Ah! It's in the technical notes for ST: TN1205 https://www.st.com/resource/en/t... looks like what you need.

 

Neil