We haven't come across any, even in our restaurant supply catalogs, and it seems unlikely that they would be available on the market.

The whole point of chocolate chips is that they retain their identity in cookies, muffins, pancakes, ice cream, etc., providing little bursts of chocolate flavor - sweet chocolate flavor. No one we know wants little bursts of unsweetened chocolate flavor, and even if you surround the chips with a sugary dough or batter, their flavor would remain and be a little jarring.

It is possible that, for ease of melting, there is a commercially packaged unsweetened chocolate chip on the market, but we haven't found it.