Semisilicon Technology Corp. v. Changzhou Jutai Electronic Co., Ltd., et al., No. 25 C 7388, (N.D. Ill. June 11, 2026) (Kendall, C.J.).
Chief Judge Kendall denied plaintiff Semisilicon’s motion for a preliminary injunction and its motion for alternative electronic service, and dismissed defendant Jutai for lack of personal jurisdiction, in this patent infringement action involving LED string lights sold on Amazon. Semisilicon, a Taiwanese patent-licensing entity, asserted two patents against five Chinese defendants—four “Amazon Defendants” that sold finished products through Amazon storefronts, and Jutai, a component manufacturer that does not sell directly to consumers.
Of particular interest, the Court held:
- Personal Jurisdiction Waiver: The four Amazon Defendants each stated in their Answers that they “denied the allegations…except that for purposes of this action only, Defendant does not contest that this Court has personal jurisdiction.” None raised lack of personal jurisdiction as an affirmative defense. The Court held this constituted an express waiver under Fed. R. Civ. P. 12(h)(1), finding that “no amount of zeal can turn this into a straight-faced” denial of jurisdiction.
- No Jurisdiction Over Component Manufacturer: Jutai, by contrast, expressly denied personal jurisdiction and raised it as an affirmative defense. The Court analyzed Fed. R. Civ. P. 4(k)(2) and the stream-of-commerce doctrine under both the Brennan and O’Connor formulations from Asahi Metal Industry Co. v. Superior Court. Because Semisilicon offered no evidence that Jutai’s products were sold or available in Illinois, products listing Jutai as manufacturer were “currently unavailable” on Amazon, and Jutai’s unrebutted declaration denied any Illinois contacts, the Court dismissed Jutai for lack of personal jurisdiction.
- Preliminary Injunction Denied on the Merits: Even with jurisdiction established over the Amazon Defendants via waiver, the Court denied a preliminary injunction because Semisilicon’s infringement showing was “facially deficient.” Semisilicon relied solely on Amazon screenshots and a 2024 cease-and-desist letter sent only to Jutai that analyzed only one of three accused products against only one of two asserted patents, with no claim charts for the remaining products or patent. The Amazon Defendants submitted an unrebutted expert declaration raising substantial questions of non-infringement on both patents, including the absence of a “predetermined voltage” limitation and an address-data comparison limitation. Because a substantial question of non-infringement was raised and unrebutted, the PI could not issue.
- Delay Undermines Irreparable Harm: Semisilicon waited approximately ten months from its cease-and-desist letter to seek a PI, and its only harm evidence was a boilerplate declaration with no specific damages figures. The Court found this delay undermined the PI.
- Electronic Service Violates Hague Convention: The Court denied Semisilicon’s motion for alternative electronic service, holding that service by email in China violates the Hague Service Convention and Fed. R. Civ. P. 4(f)(3), regardless of defendants’ litigation conduct or “waiver” arguments—a party cannot waive an international treaty’s exclusive service methods. However, because the Amazon Defendants had already appeared and litigated without preserving an objection to service, their appearance was as effective as actual service under Rule 12(h)(1).

