I have found so many of my thread breaks go back to the design itself. Check the digitizing first. Then I would go to how you have the belts held under the head. Sometimes the slightest play in the needle will cause thread breaks. I get that a lot with caps. With silk I would be using a sticky stabilizer or a wrapped hoop to be sure there is no play in the material. After that I go to the needles themselves and then the bobbin casing and then the bobbin housing. I have found small nicks in the housing can cause thread breaks. Also, if you have broken a needle, make sure all broken parts can be accounted for and removed. When all else fails, I have been known to change the thread to a different cone. I have gotten weak thread before and had to contend with breaks from a bad cone. Checking your thread path seems like a small thing but not to be overlooked. If you have more than one head, try a different head, it will give you insight as to what area you may be dealing with, thread or machine. Hope one of these ideas will help.
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