Electronics Forum | Sun Apr 19 12:54:39 EDT 2020 | davef
A-620G doesn't require 100% wetting to the thermal pad. It requires 100% wetting to the land in the end-joint area. The end joint is the portion of the solder connection that is at the top [or bottom] of the connection. Look at 7.1.3 Solder Joint A
Technical Library | 2019-07-24 23:55:32.0
Voiding is a key concern for components with thermal planes because interruptions in Z-axis continuity of the solder joint will hinder thermal transfer. When assembling components with solder paste, there is a high propensity for voiding due to the confined nature of the solder paste deposits under the component. Once reflowed, many factors contribute to the amount of voiding in a solder joint such as the reflow profile, designs of the component, board and stencil, and material factors. This study will focus on the solder paste alloy and flux combination as well as profile and board surface finishes.
SMTnet Express, July 25, 2019, Subscribers: 32,181, Companies: 10,840, Users: 24,976 Voiding Performance with Solder Pastes Containing Modified SAC Alloys for Automotive Applications in Bottom Terminated Component Assemblies Credits: Indium
Heller Industries Inc. | https://hellerindustries.com/wp-content/uploads/2018/07/Vacuum-Void-Reduction-Reflow.pdf
. The thermal cycling results are discussed in terms of the general impact of voiding on solder thermal fatigue reliability, results from the open literature, and the evolving industry standards for solder voiding
PCB Libraries, Inc. | https://www.pcblibraries.com/forum/to251aa-ipak_topic1884.html
" Flange Mount " Vertical or Horizontal calculators. The Thermal Pad is a Plated though-hole for a mounting screw that should have a direct connection to the plane. i.e.: No Thermal Relief