The angle of wetting between the solder fillet and termination or land pattern. A contact angle is measured by constructing a line tangential to the solder fillet that passes through a point of origin located at the plane of intersection between the solder fillet and termination or land pattern. Contact angles of less than 90° (positive wetting angles) are acceptable. Contact angles greater that 90° (negative wetting angles) are unacceptable.
