scope:

This document describes various via formations, materials, and design guidelines used in high density interconnects (HDI) and microvias. Microvias are processed/plated holes ≤0.15 mm in diameter.

Introduction

This document is intended to educate the user on the formation of microvias and the selection of wiring density, design rules, interconnects, and materials. It is intended to provide design guidelines for PWBs utilizing microvia technologies.

General

This document is intended to help in the selection of the preferred advanced technology for electronic packaging. The microvia PWBs are commonly referred to as build-up (BU) or sequential build-up (SBU) PWBs. These design rules apply to the BU and SBU interconnects using materials defined in IPC/JPCA-4104. The characteristics of these materials are found in Section 5.

HDI Design Selection Guideline

This guideline provides an easy to follow tutorial on the selection of HDI and microvia design rules and structures. This document brings the user through various considerations to be addressed when designing an HDI PWB, including:

• Design examples and processes

• Selection of materials

• General descriptions

• Various microvia technologies (i.e., variable depth vias and stacked vias)

Design Figures

Figure 1-1 is a color key to be used with all of the figures in this document. The key shows the color next to the material it represents.