Determination of LTCC Shrinkage Variations from Tape Manufacturer to Consumer

Abstract

Low Temperature Cofired Ceramic (LTCC) technology can be applied in numerous functions due to a wide variety of benefits, particularly related to flexibility of applications. Controlling the LTCC shrinkage tolerances in the x, y, and z dimensions is critical during manufacturing and avoids an assortment of down-stream issues that will affect yields. All manufacturers of LTCC tape provide a Certificate of Analysis (COA), which contains the results of the manufacturer's shrinkage testing so production variation can be established from lot to lot. Data from this COA is generally used as a starting point in the shrinkage predictions for manufacturing purposes; however, verification of this data must be performed prior to initiating an LTCC build. This paper investigates validation of one manufacturer's COA data and explains how shrinkage differences can occur between the COA data and the data collected during the verification process. The tracking of this data is also presented as a means to ensure proper controls are in place, and the type and style of lamination and cofiring are shown to be significant contributors to these differences. Data will then be presented in association with characterization prior to and after relocation of LTCC fabrication equipment. Additionally, the COA data can be incorporated into shrinkage estimates that will be utilized to set up process parameters, tolerances, and a control plan.