One aspect is an implantable medical device with a feedthrough assembly having an insulator and a plurality of conducting elements extending therethrough. The feedthrough assembly is placed in a case with an opening defining a narrow space therebetween. A braze material fills the narrow space, thereby hermetically sealing the feedthrough assembly to the case. One of the feedthrough assembly and the case include a feature configured to securely hold the braze and in that the implantable medical device does not include a ferrule.