You are allowed with guidelines
Ramon
J-Std-001D says in section 4.7
4.7 Mounting of Parts on Parts (Stacking of Components)
When part stacking is permitted by the assembly
drawing(s)/documentation, parts shall
not6 violate minimum electrical clearance
between other parts or components.
610-D says:
8 Surface Mount Assemblies
8.2.2.9.3 Chip Components - Rectangular or Square End Components -
1, 3 or 5 Side Termination, Termination Variations - Stacking
These criteria are applicable when stacking is a requirement.
When stacking components, the top termination area of a component
becomes the land for the next higher component.
Stacking order of mixed component types, e.g., capacitors, resistors,
needs to be established by design.
Acceptable - Class 1,2,3
* When permitted by drawing.
* All components meet the criteria of Table 8-2, features B
through W for the applicable class of acceptance.
* Side overhang does not preclude formation of required solder
fillets.
Defect - Class 1,2,3
* Stacked parts when not required by drawing.
* All components do not meet the criteria of Table 8-2, features
B through W, for the applicable class of acceptance.
* Side overhang precludes formation of required solder fillets.
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Kevin Glidden
Sent: Friday, November 03, 2006 11:17 AM
To: [log in to unmask]
Subject: [TN] Stacking chip capacitors
All,
I have an EE who wants to stack 3 chip capacitors to attain the value he
needs. I have heard of stacking being done, but have never been asked
to do it. Is it possible? What are the pit-falls? Are the IPC sepcs
that cover or discuss it?
Thanks
Kevin Glidden
Manufacturing Engineer
Astronics Luminescent Systems Inc.
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