Hi Jackson
The IPC have the definition of the min clearance , pls refer to IPC-610.

Best regards 
Alvin Zhang 
Supplier Development Engineering 
Office No. : +86-512-67612300-8713 
Mobile Phone No. : +86-13306209131 
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-----Original Message-----
From: TGAsia [mailto:[log in to unmask]] On Behalf Of Jackson Chan
Sent: Thursday, December 17, 2009 11:13 AM
To: [log in to unmask]
Subject: [TGAsia] SMT reflow - microsolder ball requirement


Dear all,

Recently, I have the discussion with the customer on the specification
of
solder ball especially at the region between the leads of IC.

Referring to IPC-A-610D, section 5.2.6.1

It states that "solder balls do not violate minimum electrical
clearance"

It came out the question on what is "minimum electrical clearance" and
"how
to relate the solder ball (in terms of size and distance) to this
minimum
electrical clearance"

IPC-2221 has the minimum electrical spacing under different voltage. For
typical voltage 0 - 15V, it is 0.13mm min.   Should we use 0.13mm
(minimum
electrical conductor spacing) to define minimum electrical clearance
stated
in the solder ball requirement per clause 5.2.6.1 of IPC-A-610D ?

Hope IPC and experts here to elaborate the solder ball requirement here.

Regards,

Jackson

  
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