If you have end overhang you cannot meet the fillet height requirement.
However, if the design does not conform to IPC specifications you cannot
use the acceptability requirements, they simply do not make sense when
taken out of context.
We have had customers send similar designs to us for assembly. Yes, the
machines can place the parts. Okay, usually the parts are not maximum
size. But, quality control is risk management. How, much risk can you
tolerate?

Subject:
        <No subject given>
    Date:
        Fri, 3 Sep 1999 12:37:41 +0200
   From:
        Grant Emandien <[log in to unmask]>



Hi All,

We have received some boards with 1206 caps placed (beautifully I might
add!) on 0805 pads. Hence only the base of the rectangular-end
terminations
are soldered i.e. no fillet meniscus on the end terminations. The
terminations do not appear to overhang the pads and hence the whole
bottom
surface area of the terminations is bedded on the soldered pad (it
covers
about half the pad area). We have done a min/max tolerance exercise on
the
1206 caps - max tolerance may result in overhang.

Is the integrity of the joint affected?

Any other factors to be considered?

J-STD-001, class 2 gives a maximum and minimum fillet height but not the

area of the fillet. As per Table 9-5, dimensions A, B, C, D, F, G nor J
appear to have been compromised.  Or do I view the situation as an
overhang
problem only, if overhang is compromised? The qty of boards affected is
small - is it best to rather inspect for overhang?

How do I interpret dimension J in Table 9-5 of J-STD-001?

Thanks
Grant

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