IIa TECHNOLOGIES PTE. LTD. v ELEMENT SIX TECHNOLOGIES LIMITED

Facts

IIa Technologies Pte Ltd and Element Six Technologies Ltd, part of the De Beers group, compete in producing synthetic diamonds by chemical vapour deposition (CVD). In HC/S 26/2016 Element Six sued IIa Technologies for infringing two Singapore patents, relying on three diamond samples it said came from IIa's products. IIa denied infringement and counterclaimed to revoke both patents. The trial judge revoked Singapore Patent No 110508 for lack of novelty and inventive step, but upheld Singapore Patent No 115872 (SG 872), filed on 20 November 2003, found it infringed, and granted a declaration, an injunction and delivery up.

SG 872 claims a low-strain single crystal CVD diamond material showing at least one of eight optical properties (Claim 1), and a growth method using 300ppb to 5ppm nitrogen in the synthesis atmosphere (Claim 62). Two limbs of Claim 1 define low birefringence partly by requiring the phase shift to stay within a narrowly defined first order, measured with a Metripol or similar instrument. It was agreed that the Metripol alone cannot tell whether a sample is within that first order. IIa appealed in Civil Appeal No 41 of 2020 against the refusal to revoke SG 872 and the infringement findings. The court arranged a technical primer and a three-day technology tutorial before hearing the appeal.

Issues

1. Whether the product claims of SG 872 cover a single product or a class of products
2. Whether the process claims, and through them the product claims, were classically insufficient for imposing an undue burden on the skilled person
3. Whether uncertainty about whether a product falls within a claim is a form of insufficiency under Singapore law, and whether Claim 1 suffered from it
4. Whether SG 872 should be revoked in its entirety

Holding

The Court of Appeal allowed the appeal, set aside the judge's declaration, injunction and delivery-up orders, and revoked SG 872 in its entirety under s 80(1)(c) of the Patents Act for insufficiency. It also overturned the findings that the three samples infringed Claim 1. The costs appeal and the costs of this appeal were left for written submissions unless agreed.

Reasoning

Construed purposively, Claim 1 covers any diamond showing at least one of eight distinct properties, and the later product claims incorporate it, so each claim asserts a monopoly over a class of products. A class is enabled only if the skilled person can make products across its whole breadth.

On classical insufficiency, the evidence of both sides' experts, and Element Six's own argument against anticipation, showed that growth conditions other than nitrogen, such as gas flow, temperature, pressure and methane concentration, materially affect the diamond produced and interact sensitively with the nitrogen level. The specification gave ranges for only two of these and a few worked examples, with no principle for calibrating them to obtain a diamond of a given quality. That was merely a starting point for an onerous research programme, and calibration was not shown to be common general knowledge. The judge erred in relying on expert evidence that addressed only two variables. All process claims were insufficient, and because SG 872 taught no other way to make its diamonds, the product claims fell with them. Experimental data from the challenger was unnecessary.

As a separate ground, the court held that a patent is also insufficient where the skilled person cannot tell whether a product or process falls within the claim even after using common general knowledge and normal claim construction. This is distinct from lack of clarity, which is not a ground of revocation. None of Element Six's suggested solutions worked: the gap theory was not shown to be common general knowledge or to apply generally, cross-polariser microscopy was imprecise and inconclusive, and the methods in a 1996 paper were not shown to work on single crystal CVD diamonds. Claim 1 was therefore uncertain, and because every other claim was defined by reference to it, the whole patent was invalid on this ground too. The infringement findings fell as the expert analysis had not shown the samples were within the first order.

From the judgment