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September 2018

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Subject:
From:
Wayne Showers <[log in to unmask]>
Reply To:
TechNet E-Mail Forum <[log in to unmask]>, Wayne Showers <[log in to unmask]>
Date:
Tue, 11 Sep 2018 15:04:00 -0500
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For what it's worth:
A fine-pitch package can be broadly defined as any package with a lead pitch finer than the 1.27mm pitch of standard surface mount packages like Plastic Leaded Chip Carriers (PLCC’s) and Small Outline Packages (SOP’s). Most common lead pitches are .65mm and .5mm.  There are even some now available in 0.4mm pitch. Devices with these fine pitches and leads on all four sides are called Quad Flat Packs (QFP’s).       Intel® Manufacturing Enabling Guide 1-7  May 2010

A little dated, but the source of the fine-pitch definition.

For a last look, I would use 0.5mm and 2mm respectively if you are needing a dividing line for internal measurement.  But as you original problem stems as much from pad-to-pad spacing as it does lead spacing, this would be best expressed as less than 0.20mm pad spacing for SMT and 0.50mm pad spacing for through-hole.  

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