Depends largely on the base materials that you are brazing, the type of brazing process employed, and the times at temperature required to properly flow the braze alloy.  Since Type II boundaries are typically formed in the base material's HAZ, then understanding the microstructural changes in the HAZ should answer your question.  If you need to understand properties, I've seen some work done on various base materials in a 'Gleeble" to identify the new base metal structure and loaded in different environments (hydrogen charged, etc) to see when deleterious effects occur.  I'm sorry, but I will not be able to share any of the testing data.

So, it is rather difficult to answer your question with the limited amount of information.  All I can say is that it is possible to form type II boundaries from particular brazing processes on particular base materials.

Kindest Regards,

Dan