Hi Alvin,



Thank you for your response.



I also read this table in IPC-610D before.    You think that we should 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.  Is that mean the solder ball should be located at least 0.13mm

distance from the pad of IC or have different meaning.



I raise one example - 0.5mm pitch IC and spacing between the pads of IC

lead is 0.22mm. The size of solder ball is 0.1mm.

If the solder ball is at the middle of space between the pads for lead, it

is impossible to have 0.13mm clearance from either side of IC pad.  It also

implies that 0.5mm ptich , 0.4mm ptich or smaller pitch for IC does not

allow  the presence of any solder ball .  It seems that it is not so

feasible to have 100% "Pass" in every board.



Jackson









                                                                           

             "Alvin(Suz)                                                   

             Zhang(Suzhou)"                                                

             <Alvin-Suz.Zhang-                                          To 

             [log in to unmask]         "Jackson Chan"                      

             nics.com>                 <[log in to unmask]>      

                                                                        cc 

             2009/12/17 上午           "Asia Committe Task Group Forum"    

             11:34                     <[log in to unmask]>                    

                                                                   Subject 

                                       RE: [TGAsia] SMT reflow -           

                                       microsolder ball requirement        

                                                                           

                                                                           

                                                                           

                                                                           

                                                                           

                                                                           









Hi Jackson

Pls refer to this.

(Embedded image moved to file: pic09930.gif)



Best regards

Alvin Zhang

Supplier Development Engineering

Office No. : +86-512-67612300-8713

Mobile Phone No. : +86-13306209131

[log in to unmask] | www.flextronics.com | "Creating

value that increases customer competitiveness"





-----Original Message-----

From: Alvin(Suz) Zhang(Suzhou)

Sent: Thursday, December 17, 2009 11:28 AM

To: 'Jackson Chan'

Cc: 'Asia Committe Task Group Forum'

Subject: RE: [TGAsia] SMT reflow - microsolder ball requirement



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

[log in to unmask] | www.flextronics.com | "Creating

value that increases customer competitiveness"



-----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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