Statistical insights on patent revocation cases in Korea

The ex parte patent revocation procedure was introduced on March 1 2017 as an alternative option for challenging an issued patent in Korea. Although the ex parte patent revocation procedure in Korea is similar to the patent opposition system in Japan, there are certain differences therebetween, notably, with respect to the grounds for revocation: the ex parte patent revocation procedure can only be instituted for (i) lack of novelty/inventiveness based on printed publications that have not been cited by the examiner during the prosecution of the patent, and (ii) violation of the (extended) first-to-file rule.

This article examines the statistical trends of the ex parte patent revocation procedure in Korea, based on cases petitioned during the first five years of implementation; i.e., from March 2017 through December 2021.

During the initial five-year period, there were a total of 733 patent revocation cases instigated (about 150 cases per year). The statistics show that 45% of the respondents – i.e., the patentees – in these patent revocation cases were foreign entities, among which the percentage of Japanese patentees was around 58%.

The most common technical field for these patent revocation cases resided in Section C of the International Patent Classification (IPC) – i.e., chemistry/metallurgy – with 30% of the cases belonging to that field. The second most common field was Section H of the IPC – i.e., electronics – with 23% of the cases. These statistics reflect the current industry development trend in Korea – i.e., heightened competition in the fields of electronic materials and electronics – and further underscore that Japanese companies are front-runners in the field of electronic materials.

During the five-year period, the Trial Board of the KIPO rendered decisions in 599 patent revocation cases, resulting in 181 patent (about 30.4%) revocations. The revocation rate is lower than the invalidation rate (52.3% in 2021) through invalidation trials, but significantly higher than the revocation rate in Japanese opposition proceedings (revocation rate = number of revocation decisions / (number of revocation decisions + number of dismissal decisions + number of invalidation decisions + number of withdrawn cases)).

*Before the board renders a decision to revoke the challenged claim(s), the patentee is to be notified of the reason(s) for revocation and given an opportunity to submit a response thereto (possibly together with amendment to the specification, claims and/or drawings).

In a nutshell, (i) around 30% of the cases were dismissed (i.e., the challenged patents were maintained) without the issuance of any notice of reason for revocation by the board, (ii) 34% of the challenged patents were maintained with claim amendment, (iii) 4% were maintained without any claim amendment, (iv) 17% were entirely or partially revoked even with claim amendment, and (v) 15% of the challenged patents without any claim amendment were entirely or partially revoked. These statistics underline the difficulty of maintaining claims without any amendment once the Board issues a notice of reason for revocation.

Among the 181 patent revocation decisions rendered by the Trial Board, 44 cases (about 24%) were appealed by the patentees to the Patent Court. Among them, the Patent Court reviewed 33 revocation appeal cases during the five-year period, deciding 13 cases in favour of the patentees (about 39%).