Laminate Characterization Measurement Testing

摘要

THIS IS PART three in a series that examines how the industry at-large characterizes laminates. It's true such things are of little interest below 1GHz, but I suspect the relative comfort of the sub-GHz world has slipped into the distant past for many of us. Part Ⅰ summarized the "anarchy" that permeates this part of the PCB design world. Part Ⅱ, last month's column, pointed out a dozen different "standards" can be used to characterize Dk and Df. In fact, there's little evidence to suggest the standardization process has led the industry to true standards. To me, "standard" means that if I measure something in Taipei, Tokyo, Toulouse or Toronto, I'm going to get pretty close to the same result if I follow a "standard" test method. That's not what we have. Here in Part Ⅲ, we'll focus primarily on the electric-field (E-field) orientation of the measurement equipment.