scope:

This standard describes design and assembly guidance for implementing bottom termination components (BTCs). The focus of the information contained herein is on critical design, materials, assembly, inspection, repair, quality and reliability issues associated with BTCs.

This standard applies only to BTCs, which are components with planar terminations under the body with or without wettable side terminations or flanks. Examples of BTCs include small-outline no-lead (SON), dual-flat no-lead (DFN), quad-flat no-lead (QFN), land grid array (LGA), etc. (see Section 4).

Purpose

The purpose of this standard is to provide useful and practical information to those who use or are considering using BTCs. The target audiences for this document are physical designers, process engineers, reliability engineers and managers who are responsible for design, assembly, inspection and repair processes of printed boards and printed board assemblies. Information described in this standard enables high-quality and highly reliable BTC assembled devices operating within an electronic system.

This document also describes how to successfully implement robust design and assembly processes for printed board assemblies using BTCs as well as ways to troubleshoot some common anomalies which can occur during BTC assembly. For accept/reject criteria and requirements for BTC assemblies, see J-STD-001 and IPC-A-610.