Preheat oven to 200°F.  Combine zucchini, vinegar, and oil in a medium bowl, tossing to coat well. Let stand 10 minutes. Place zucchini slices in a single layer on 2 baking sheets lined with parchment paper; sprinkle evenly with salt. Bake at 200°F for 2 to 2 1/2 hours or until chips are dried, crisp, and lightly golden, flipping chips halfway through baking. Remove from oven; cool completely.