Author Topic: Weird stencil pattern  (Read 1446 times)

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Offline BootalitoTopic starter

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Weird stencil pattern
« on: December 10, 2018, 11:55:09 pm »
I just ordered by first stencil of JLPCB and the 0805 parts have a weird indent in them.  Here is a picture of a row of (5) 0805 resistors


Is this normal?

Here is a screenshot of the "TopPasteLayerMask" from EasyEDA, which should be what the stencil should look like.  I have a couple of TH parts and I verified that there is no mask in those locations.
« Last Edit: December 10, 2018, 11:59:39 pm by Bootalito »
 

Offline SMTech

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Re: Weird stencil pattern
« Reply #1 on: December 11, 2018, 12:27:03 am »
Its not an uncommon thing to do, this reduces the amount of solder under the device which in turn reduces the chance of getting mid chip solder balls. No idea if this is typical of JLC or if they have seen something about your design that makes them think you might need it.
 

Offline mrpackethead

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Re: Weird stencil pattern
« Reply #2 on: December 11, 2018, 06:00:08 am »
That is quite a standard paste pad for a larger SMT ( 0805 and above ) part.    that being said, i dont' use them and solder balls have never really been an issue for me.   
That being said, i put a LOT of work into my stencil design, and i do not want any modifications made them.    When i order i place very explicit instructions in the notes, which seems to work.

" DO NOT ADJUST  APERTURES.  APPLY NO REDUCTION. MAKE AT 100% AS PER SUPPLIED GERBER "       
On a quest to find increasingly complicated ways to blink things
 

Offline BootalitoTopic starter

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Re: Weird stencil pattern
« Reply #3 on: December 11, 2018, 12:42:41 pm »
That is quite a standard paste pad for a larger SMT ( 0805 and above ) part.    that being said, i dont' use them and solder balls have never really been an issue for me.   
That being said, i put a LOT of work into my stencil design, and i do not want any modifications made them.    When i order i place very explicit instructions in the notes, which seems to work.

" DO NOT ADJUST  APERTURES.  APPLY NO REDUCTION. MAKE AT 100% AS PER SUPPLIED GERBER "     
FYI
I misspoke: they are 0603 size. Would you say they are still appropriate, or less so?

And thanks for the advice about the comment when buying the stencil.
 

Offline eb4fbz

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Re: Weird stencil pattern
« Reply #4 on: December 11, 2018, 03:42:56 pm »
That's the recommended paste pattern for 0603. They have optimized the stencil for you.
 


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