What is Blutter Coat
Blutter coat is an external layer of resin that is applied over the reinforcing structure of a base material. This process involves flow coating the material onto the board and is commonly used for low volume applications, finishing, and repair purposes. The finish of a Blutter Coat may not meet high cosmetic standards and can be susceptible to defects such as the formation of bubbles. The thickness of the coating also tends to vary, with skilled operators typically achieving a more consistent application.
Blutter coat can also describe a localized swelling and separation that occurs between any of the layers of a laminated base material or between the base material and conductive foil. This separation, known as delamination, can also manifest as a separation between the solder mask layer and the conductive pattern. It is crucial to address and prevent such delamination issues as they can negatively impact the overall integrity and functionality of the PCB.