Cook soba noodles according to package directions. Drain, and rinse with cold water. Place in a large bowl. Toss in cilantro, cucumbers, and carrots, and set aside.
In a small bowl, whisk together the soy sauce, vinegar, lime juice, garlic, brown sugar, red pepper flakes, and sesame oil.
Pour dressing over noodles and toss to combine. Top with sesame seeds. Cover and place in refrigerator for at least 1.5 hours.