Not Specified - Class 1
Acceptable - Class 2
Defect - Class 3
• As an exception to the fill requirements of Table 7-4, the
minimum permissible vertical fill of a PTH is 50% or 1.19 mm
[0.047 in], whichever is less, for Class 2 products provided
the following conditions are met:
– The PTH is connected to thermal or conductor layers that
act as thermal heat sinks.
– The component lead is discernible in the Side B solder
connection of Figure 7-91.
– The solder fillet on Side B of Figure 7-91 has wetted 360°
of the PTH barrel wall and 360° of the lead.
– Surrounding PTHs meet requirements of Table 7-4.
Note: Less than 100% solder fill may not be acceptable in
some applications, e.g., thermal shock, electrical performance.
The user is responsible for identifying these situations
to the manufacture