The IPC-7093A standard outlines design, assembly, and reliability guidelines for Bottom Termination Components (BTCs) such as QFN and LGA packages, emphasizing optimized reflow profiles and solder mask-defined thermal pads. It serves as an updated guide for addressing specific assembly challenges and voiding, with purchasing options available at Standards Supply or similar authorized vendors. IPC 7093A PDF - Engineering Standards Download
Assembly Processes: Best practices for solder paste printing, stencil design (such as "window pane" apertures), and component placement. ipc-7093a pdf
The primary goal of the document is to provide a comprehensive set of "best practices" to minimize common defects like voiding, poor solder wetting, and component tilting. Key Changes in the "A" Revision Increased Density : Embedding components allows for higher
Solder paste volume is the #1 variable in BTC assembly. The standard recommends: potentially improving reliability.
Reliability Data: New research and data points regarding the long-term reliability of BTC solder joints under thermal cycling. Critical Focus Areas
BTCs are a category of surface-mount devices whose electrical and thermal connections are located on their bottom surface, typically as exposed metal pads. Common examples include: