The New IPC HDI (Microvia) Design Guideline (IPC-2315)

ABSTRACT The new IPC HDI Design Document, “IPC-2315 Design Guide for High Density Interconnect Structures and Microvias” is a remarkable document developed over the last two years. It is a departure from traditional IPC documents in that it carries in it a lengthy tutorial on how to calculate and select the proper design rules and structures for very high density assemblies. This paper describes the new design guide and the various design rules for different HDI structures. The topics covered are: ♦ Definitions and classification of microvias ♦ Density evaluation and routability predictions, with/examples ♦ Material selection and specifications ♦ Type I HDI Structure, alternatives and design rules ♦ Type II HDI Structure, alternatives and design rules ♦ Type III HDI Structure, alternatives and design rules ♦ Staggered vias, via-in-pad design rules ♦ Special HDI design rules (stacked vias, co-lamination and conductive pastes) This paper complements the other two new IPC HDI standards, IPC-4104 Specification for HDI Materials and IPC-6016 Qualification and Performance Specification for HDI.