Date : 18/10/96 14:33
Msg From: S MAITRA
Dear Technetters,

We are looking for following clarifications and would appreciate if
someone can reply on this:

1) Under section soldering clause no. 4.2.1 (exposed basis metal) of
IPC-A-610B clarify the non conforming defect for class 1,2,3
  a) Is copper exposed to be treated as a defect if on EMI pad?
  b) Is copper exposed to be treated as a defect if on Mounting hole 
     (explain for top and bottom side both)?
  c) Is copper exposed  also to be treated as a defect if any where  
     on the board except traces?

2) Under section IPC-A-600D section 11.6 Solder Mask Cracking and
Scratches for acceptable condition class 1,2 & 3.
   Please clarify conductive pattern in reference to exposed copper.

In other words as per our understandings IPC-A-610B does not allow
any copper exposed on assembled boards on either of the sides. Does
this neccesarily mean that under IPC-A-600D also no copper exposed is
allowed on either side of the board ? Is a pin point Copper exposed
also a reject on assembled board and under what magnification and
lumminance should this be inspected? 

We will  really appreciate your quick response on this.


S. MAITRA
Deputy General Manager - QA
ALtos India Ltd.
Fax :91-124-340842/91-124-340892/91-11-6488591
Phone :91-124-340867/340868/340872
E-Mail:[log in to unmask]

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