Friction Back Plate Design/Manufacturing/Quality - Key Attributes for Better Brake Performance 2017-01-2506

Friction material back plate design, manufacturing and consistent quality are some of the key attributes for better brake performance. Historically, the auto industry’s focus on back plate quality has been limited to drawing dimensions. Recently, vehicle manufacturers across the globe are tightening caliper performance criteria to achieve near zero drag for fuel consumption regulations and improved NVH to attract end customers. To meet these new stringent requirements, friction and back plate suppliers need to focus, in more detail, on how to improve the backing plate quality and better understand the interface characteristics of back plate/pad assembly to caliper performance. While many key characteristics of the back plate were identified in past assembly design process, there has been vague understanding to connect with caliper performance, thus, the definition of back plate quality has been limited to basic dimensional measurement. Thus, the critical aspect of these characteristics was not clearly understood, and largely overlooked through pad assembly design and development. In this paper, the authors will discuss in detail some of those critical aspects of back plate quality beyond basic dimensions. For example, back plate geometry - bow/flatness and abutment edge/surface condition, back plate stability under temperature environment - thermal stress relief and back plate thermal expansion, and its’ bow/flatness change over the entire pad assembly manufacturing process. The authors will also try to bridge the characteristics to caliper performance and their impact to NVH, including the impact to shim bonding and other caliper performance attributes, via some of their recent correlation studies. Finally, the authors will present their proposal to improve the back-plate quality and incorporate these critical aspects into the caliper development process.