Sufficiency Of Disclosure: New Considerations Under Singapore Patent Law

• Law Firm: Davies Collison Cave
• Subject Matter: Intellectual Property, Litigation, Mediation & Arbitration, Patent, Trials & Appeals & Compensation
• Author: Mr Richie Tay and Kian Hoe Khoo
• Published date: 09 March 2023

Sufficiency of disclosure is a cornerstone of patent law and is part of a "patent bargain" for providing a limited-term monopoly over an invention. In exchange, the inventor or patentee has to teach, in the patent specification, how to work or make the invention so that the public can learn from and eventually build on this knowledge. The Singapore Patents Act stipulates that a specification must disclose an invention in a manner which is clear and complete for the invention to be performed by a skilled person, and insufficient disclosure is a ground for patent revocation in Singapore. In IIa Technologies Pte Ltd v Element Six Technologies Ltd [2023] SGCA 5, the Court of Appeal clarified the requirements for sufficiency under Singapore patent law.

Background

Element Six Tech Ltd and IIa Tech Pte Ltd are competitors in the production of synthetic diamonds grown using chemical vapour deposition ("CVD"). The former is part of the De Beers Group of diamond producers while the latter is a Singapore company established in 2005. In 2016, Element Six filed suit against IIa, claiming infringement of two of its Singapore-registered patents, No. 115872 ("SG 872") and 110508 ("SG 508"). In its defence, IIa filed a counterclaim disputing the validity of both patents and seeking their revocation.

In Element Six Technologies Ltd v IIa Technologies Pte Ltd [2020] SGHC 26, the High Court revoked SG 508 for lacking novelty and inventive step. However, SG 872 was found to be valid and specific claims in that patent were found to be infringed by IIa. IIa filed an appeal to challenge the Judge's decision on validity and infringement, which is the subject of the present case.

Claim 1 and claim 62 of SG 872 were the pivotal claims in dispute. Claim 1 is directed to a CVD single crystal diamond material exhibiting at least one of eight quantifiable optical properties. One of these properties is characterised by the parameter δ and the values it may take. Claim 62 is directed to a method of growing the diamond material in the product claims and includes providing a synthesis atmosphere containing 300 ppb to 5 ppm nitrogen. IIa contended that both claims 1 and 62 did not fulfil the sufficiency requirement.

Law of sufficiency in Singapore

The Court of Appeal took the opportunity to set out general principles applicable to the legal requirement of sufficiency in Singapore. First, the burden of proving insufficiency rests on the party challenging the validity of a registered patent...