Understanding footprint pattern dimensions in datasheet

Thread Starter

spinnaker

Joined Oct 29, 2009
7,830
I am trying to build a pattern for a Vishay TCRT5000. It has a rather odd shape. The component has two plastic mounting tabs. One of which is marked with the blue circle. It does not seem to be a dimension since it measures closer to .9mm and confirmed into the other dimensions below.

Also I know I recognize that symbol but I have been trying to search my memory banks to its meaning. It sort of looks like phi but I don't think that is it.

upload_2017-1-23_22-19-6.png




From these second set of dimensions it looks like that tab is .95mm wide?
upload_2017-1-23_22-17-7.png
 

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wayneh

Joined Sep 9, 2010
17,496
I don't know why you need a hole that is 2.5mm for a tab that is 0.95, but that seems to be what it's showing. Maybe to allow plenty of room for placement "slop"?
 

Thread Starter

spinnaker

Joined Oct 29, 2009
7,830
I don't know why you need a hole that is 2.5mm for a tab that is 0.95, but that seems to be what it's showing. Maybe to allow plenty of room for placement "slop"?

So is it a 2.5mm hole? Is that what the symbol means?

They are 2 spring type tabs with a notch at the end of each tab. so maybe it is 2.5mm for manufacturing purposes to get the tabs in place.
 

GopherT

Joined Nov 23, 2012
8,009
So is it a 2.5mm hole? Is that what the symbol means?

They are 2 spring type tabs with a notch at the end of each tab. so maybe it is 2.5mm for manufacturing purposes to get the tabs in place.
Does the 2.5mm circle represents the orientation of the two optical components on the top of the package?

The bottom drawing shows the pins are 0.95mm diameter.
 

Thread Starter

spinnaker

Joined Oct 29, 2009
7,830
Does the 2.5mm circle represents the orientation of the two optical components on the top of the package?

The bottom drawing shows the pins are 0.95mm diameter.

No they would be side by side horizontal on the footprint posted.

Yes 9.5mm was mentioned in my first post.


And I am still trying to find out what the little symbol is. I know I have seen it before.
 

GopherT

Joined Nov 23, 2012
8,009
No they would be side by side horizontal on the footprint posted.

Yes 9.5mm was mentioned in my first post.


And I am still trying to find out what the little symbol is. I know I have seen it before.
You mean the circle with hash through it? It means diameter. Or was there another symbol?
 
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