Patent Enablement and Sufficiency in Singapore

I was invited to give a talk recently on patent enablement and sufficiency in Singapore.

The talk was presented at a webinar on 22 July 2024, jointly hosted by the Association of Singapore Patent Attorneys (ASPA) and the Capital Intellectual Property Services Association (Beijing, China).

In my talk, I discussed the judgement of the Singapore Court of Appeal in IIa Technologies Pte Ltd v Element Six Technologies Ltd.

This blog post sets out a transcript of the talk presented to the audience of Singapore and Chinese patent and trade mark attorneys.

Transcript of Talk on Patent Enablement and Sufficiency

Good afternoon, ladies and gentlemen. My name is Khoo Chong Yee from Cantab IP Pte Ltd. I’m a European Patent Attorney, a UK Chartered Patent Attorney and a Singapore Patent Attorney.

Today, I am going to speak on patent sufficiency in Singapore. I will focus on the judgement of the Singapore Court of Appeal in the IIa Technologies and Element Six case.

What We’ll Cover

First, I will tell you a bit about the background to this litigation. I will talk about the patent in suit and the technical background underlying the patent.

I’ll then describe the provisions relating to sufficiency in the Singapore Patents Act and how the Court of Appeal applied these to the case in question.

Finally, I will end the talk with some comments on the case and recommendations for best practice to avoid sufficiency issues.

Background

Both IIa Technologies and Element Six are in the business of producing synthetic diamonds. Element Six owned the two patents shown here and sued IIa Technologies at the High Court of Singapore. In return, IIa Technologies counter-sued and alleged that the patents were invalid and not infringed.

The High Court judge found that the first patent was invalid because it lacked novelty or inventive step. As Element Six didn’t lodge an appeal, the patent was revoked in its entirety.

On the other hand, the High Court judge found Singapore Patent 115872 to be both valid and infringed. IIa Technologies appealed to the Court of Appeal on these findings.

Singapore Patent 115872 - Technical Background

I’ll now take you through some of the technology underlying Singapore Patent 115872. The patent discloses synthetic diamonds made using a process called chemical vapour deposition. In this process, you place a substrate, which is a seed, in a reactor with gases. These gases comprise a mixture, including methane and hydrogen. Energy is then applied to the gas mixture to break the molecules into plasma containing carbon. The carbon is then deposited on to the substrate, allowing the synthetic diamond to grow layer by layer.

The claims in Singapore Patent 115872 were directed to a diamond with certain characteristics, which I will talk about in detail later. There were also claims to a method of making such a synthetic diamond.

Sufficiency - Section 80(1) of the Singapore Patents Act

To give effect to the “patent bargain”, the Singapore Patents Act requires a patent specification to enable the invention claimed. The sufficiency provisions are set out in Section 80 of the Singapore Patents Act.

Section 80(1) makes clear that a patent may be revoked if the specification does not disclose the invention clearly and completely for it to be performed by a person skilled in the art. Importantly, you should be aware that the Act does not allow revocation simply on the basis that the claims are not clear or that they are not supported by the description.

Sufficiency Analysis

The Court of Appeal included a useful review of the law relating to sufficiency in its judgement.

At paragraph 114, the Court of Appeal reminds us that the disclosure of the specification needs to enable the invention across the whole breadth of the claim. While some degree of trial and error and experimentation may be allowed, this must not pose an undue burden on the person skilled in the art.

The Court of Appeal sets out the steps to be taken for a sufficiency analysis.

First, we are asked to adopt the mantle of a person skilled in the art, who has the common general knowledge that comes with this position.

Second, we apply the principles of claim construction to construe the claim and determine what it means and what it covers.

Third, we take the common knowledge of the person skilled in the art at the date of filing and combine it with the disclosure of the specification.

We then ask ourselves whether the person skilled in the art is able to perform the invention over the full scope of the claim.

Claim 62 - Method

Turning to the claims, I’ve set out the text of Claim 62, which is the main method claim, on the slide.

The claim is long and somewhat complicated, but I want you to concentrate on the key features.

“A method of producing a CVD diamond material suitable for optical applications and according to any one of the preceding claims, which method includes the steps of:

providing a substrate substantially free of crystal defects,
providing a source gas,
dissociating the source gas to produce a synthesis atmosphere which contains 300 ppb to 5 ppm nitrogen, calculated as molecular nitrogen, and allowing homoepitaxial diamond growth on the surface which is substantially free of crystal defects wherein the surface damage of the substrate is minimised by including a plasma etch on the surface on which homoepitaxial diamond growth is to occur, whereby a density of defects at the surface of the substrate is such that surface etch features related to the defects is below 5 x 103/mm2, wherein the level of nitrogen is controlled with an error of less than 300 ppb (as a molecular fraction of the total gas volume) or 10% of the target value in the case phase, whichever is the larger, and wherein the level of nitrogen is selected to be sufficient to prevent or reduce strain generating defects whilst being low enough to prevent or reduce deleterious absorptions and crystal quality degradation, thereby producing a CVD single crystal diamond material meeting the requirements of one or more of claims 1 to 61.”

Claim 62 is directed to a method of producing a diamond by chemical vapour deposition. The claim also sets out certain conditions for the method to be performed, such as the amount of nitrogen in the atmosphere, the tolerance by which this is controlled and the fact that one needs to select the right level of nitrogen, which is high enough to prevent defects while being low enough to prevent absorptions and degradation.

Sufficiency of Claims

The Court of Appeal found, however, that in addition to the conditions set out in the claim, there were a number of other conditions which affected the growth of the diamonds. Crucially, the specification did not disclose what these other conditions were, or how they could be determined.

The Court of Appeal found that this placed an undue burden on a person skilled in the art to establish the conditions. The conclusion is that the specification does not enable the person skilled in the art to perform the claimed methods.

The Court of Appeal referred to this as “classical insufficiency”. The Court of Appeal also found that the product claims also lacked sufficiency, for the same reasons.

In addition to finding that the claims are classically insufficient, the Court of Appeal found that the claims also lacked sufficiency because they were “ambiguous” or “uncertain”.

Sufficiency - Insufficiency due to “Uncertainty” or “Ambiguity”

Insufficiency due to uncertainty arises when the specification does not provide enough information, with the result that a person skilled in the art cannot determine if something falls within the claims or not.

The Court of Appeal referred to the United Kingdom House of Lords judgement in Kirin-Amgen v Hoechst Marion Roussel.

Here, there was a claim to a recombinant erythropoietin, which was required to be heavier than a reference urinary erythropoietin. The issue was that there are a number of different types of urinary erythropoietin and the specification did not tell you which specific urinary erythropoietin to use as the reference. Depending on which one you chose, the recombinant erythropoietin you are testing may have a higher or lower molecular weight. Because a person skilled in the art cannot determine if something falls within the claim or not, the claim is insufficient.

The Court of Appeal made clear that this type of insufficiency, which it referred to as insufficiency due to uncertainty is distinct from “classical” insufficiency.

Claim 1 - Product

With regard to the product claim,

“A CVD single crystal diamond material which shows at least one of the following characteristics, when measured at room temperature (nominally 20˚C):…

ii) a low optical birefringence, indicative of low strain, such that in a sample of a specified thickness of at least 0.5 mm and measured in a manner described herein over a specified area of at least 1.3 mm x 1.3 mm, the modulus of the sine of the phase shift, |sin δ|, for at least 98% of the analysed area of the sample remains in first order (δ does not exceed π/2) and the |sin δ| does not exceed 0.9;
iii) a low optical birefringence, indicative of low strain, such that in a sample of a specified thickness of at least 0.5 mm and measured in a manner described herein over a specified area of at least 1.3 mm x 1.3 mm, for 100% of the area analysed, the sample remains in first order (δ does not exceed π/2), and the maximum value of Δn[average], the average value of the difference between the refractive index for light polarised parallel to the slow and fast axes averaged over the sample thickness, does not exceed 1.5 x 10-4;…”

you will see that it requires the diamond to have certain properties.

These are that the phase shift δ does not exceed π/2; and the modulus of the sine of the phase shift |sin δ| does not exceed 0.9. The claim also tells you that these measurements should be determined as described in the specification.

What then does the specification say as to how these values are to be measured?

Claim 1 - Insufficient due to “Uncertainty”

If you remember your trigonometry, however, you will know that a single |sin δ| value may correspond to multiple δ values. As shown in the slide, different values of δ on the x-axis correspond to the same value of |sin δ| on the y-axis.

The one-to-many mapping means that a person skilled in the art cannot know whether δ is below π/2, as required by the claim. The Court held that Claim 1 is not enabled by the specification, because of this uncertainty. The Court of Appeal did not accept the argument that a person skilled in the art could determine the value of δ by other means.

Comments

For the first time, the Singapore Courts have recognised the concept of insufficiency by uncertainty.

The Court of Appeal also discussed another type of sufficiency, Biogen sufficiency, recognised in English law. Here, the claim is insufficient if there are other ways to work the invention, which do not owe themselves to the disclosure of the specification. Alternatively, there is Biogen insufficiency if the breadth of claim is too broad, so that it is not justified by the technical contribution of the patent. The Court of Appeal declined to state whether Biogen sufficiency is a feature of the law in Singapore.

Issues being raised in other jurisdictions, such as plausibility, have not - to my knowledge - been raised in Singapore and it is unclear how the Singapore Courts will deal with these.

As some of you know, sufficiency is a very important issue in the life sciences area. Much of the litigation giving rise to the legal principles underlying sufficiency has occurred in the biotech and pharma fields. However, the IIa Technologies v Element Six litigation in Singapore - over what is essentially an engineering or physics case - shows that sufficiency is also relevant in other fields, not just in the life sciences.

Finally, some of you may be aware of an earlier case (“Sunseap”). Here, the judge declared that if “all the independent claims in a patent have found to be invalid” then “it follows that the dependant claims must also fall away and the patent as a whole must be regarded as invalid”. This is of course contrary to the law and practice in other parts of the world and it is fair to say that it has caused consternation among the patent attorney profession in Singapore.

The Court of Appeal however declined to say whether the judge’s comments in the Sunseap case are good law.

You should be aware that, at IPOS, the patent examiners will generally raise insufficiency objections under “lack of support” of the claim by the description.

Practice Tips

I shall end my talk by setting out what I believe are good practices to adopt when drafting patent specifications. These will hopefully minimise sufficiency objections being raised during prosecution and any litigation.

The most important thing to do is to make sure that you draft a description that matches the scope of the claim. Generally, the broader the claim sought, the more disclosure you need to make.

In the description, include as much information as you have access to from the inventors, and which you can think up. To do this, it is helpful to imagine that you are a person skilled in the art, who is the notional addressee of the patent. How much information do you know (common general knowledge)? How much extra instruction do you need to be given in order to perform the invention?

When drafting claims, think about the words you use in the claim - do they give rise to any ambiguity? If there is any doubt, set out a definition in the description.

Finally, remember that it is likely that the specification you draft does not only need to meet your local law, but also laws of other countries around the world, for example the best mode requirement under US patent law.

I hope these suggestions for best practice are useful.

Resources

I have included on this slide some resources which you may wish to refer to.

IIa Technologies Pte Ltd v Element Six Technologies Ltd [2023] 1 SLR 987; [2023] SGCA 5
Sunseap Group Pte Ltd v Sun Electric Pte Ltd [2019] 1 SLR 645
Singapore Patents Act
Singapore Patents Rules
Examination Guidelines for Patent Applications at IPOS

Thank you for listening to my talk. I am happy to take any questions later. You can also email me at our email address [email protected] if you have any questions on the topics discussed.

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