Recognizing Japan's leadership in microvia substrate production, the IPC HDI Committee chose to adopt JPCA-BU01 as IPC/JPCA-6801. The adoption of this document is a part of the ongoing efforts of the IPC HDI Committee and JPCA Build-Up PWB Committee to ensure global consistency in the terminology, requirements and test methods for HDI and microvia applications. IPC/JPCA-6801 lists terms specific to HDI and test methods for CTE for materials and HDI PWBs, peel strength and thermal shock. Also included is a design criteria table and background information for the development of a standard for HDI PWBs.