Judge Lucy Koh does not sound at all skeptical of a consumer class seeking to recover $5 billion in antitrust damages from Qualcomm Inc.

Describing the plaintiffs’ evidence variously as “substantial,” “strong” and “compelling,” Koh, of the U.S. District Court for the Northern District of California, on Thursday certified an estimated class of some 240 million individuals who’ve purchased cellphones at prices allegedly inflated by Qualcomm’s chip licensing policies.