Imagine this scenario:
You hired a patent attorney, filed your application, passed the rigorous examination by the Korean Intellectual Property Office (KIPO), and finally received your registration certificate. You feel secure.
But later, during a patent dispute or lawsuit, the judge tells you:
“Your patent is invalid because the description is unclear.”
It sounds like a nightmare, doesn’t it? You might ask, “I paid an expert to write this! How can it be invalid just because of some wording?” Unfortunately, this happens more often than you might think.
In patent invalidation trials, patents are often struck down not because the invention lacks novelty or inventiveness, but simply because the specification (description) was too vague.
Today, I want to discuss why “writing well” is just as critical as “inventing well” in the world of IP.
The “Quid Pro Quo” of Patents
A patent is a deal between the inventor and the public. You get a monopoly for 20 years, and in exchange, you disclose your technology to the public.
Korean Patent Act Article 42(3)(1) mandates:
“The description of the invention must be clear and detailed enough for a person skilled in the art to easily carry out the invention.”
This is known as the Enablement Requirement. If a competitor reads your patent and cannot reproduce the result without excessive experimentation because your instructions are vague, your patent is invalid. It doesn’t matter how ground-breaking the idea was.
A Lesson from the US: The “Simultaneously” Trap
Before we look at the recent Korean case, let me share a famous anecdote that haunts every patent attorney.
There was a US case where a patent was invalidated because of the word “Simultaneously.”
The court ruled that the term was unclear because it didn’t define how much error was allowed. Did it mean “at the exact same microsecond” or “within a reasonable margin”? Because this wasn’t defined, a perfectly good technology lost its protection.
This pressure is why we, as patent attorneys, obsess over every single word.
The Korean Supreme Court Case: Polycrystalline Silicon
Recently, the Korean Supreme Court finalized a decision invalidating a patent for “Method for Manufacturing Polycrystalline Silicon” due to unclear specifications.
The Invention (The Claim)
The invention involved a method of producing silicon using a Siemens reactor. The key feature was controlling the process based on a specific formula called the “Archimedes number (Ar).”
The Formula:
The Claim: The patent claimed that keeping this “Archimedes number” within a specific range (relative to the Fill Level of the reactor) would optimize silicon deposition.
The Problem: “Parameter Invention”
This is what we call a Parameter Invention. The inventor created a new variable (the specific Archimedes number calculation) to define the invention.
The Supreme Court has a strict rule for these:
“If an invention uses a new parameter or variable, the specification must clearly explain how to measure the values needed to calculate that parameter. If a person skilled in the art cannot figure out the measurement method without excessive experimentation, the patent is invalid.”
The Verdict: Invalid
The Supreme Court ruled against the patent holder.
Why?
The formula for the Archimedes number required values for:
- Volume of the Rod (Vrod)
- Temperature of the Reactor Wall (Twall)
- Flow Rate (Q)
However, the patent specification did not explain “how” to measure these specific values inside the reactor during the process.
- Where exactly on the wall do you measure the temperature?
- How do you measure the rod’s volume while the reaction is happening?
Since these measurement methods were missing, no one could accurately calculate the “Archimedes number” to reproduce the invention. Thus, the patent was declared invalid.
Conclusion: Drafting is the “Flower” of Patent Law
Ideas, novelty, and inventiveness are crucial. But how accurately and meticulously you describe that idea is equally important.
In trademark law, the strategy of “how to file” (to avoid rejection) is the hardest part.
In patent law, the strategy of “how to write the specification” (to survive invalidation) is the ultimate challenge.
This is why patent drafting is often called the “flower” of a senior attorney’s career. It requires not just technical knowledge, but a mastery of language and logic. A good patent attorney must be a good writer.
If you are worried about the strength of your patent specifications or facing a validity challenge, you need an expert who understands these strict requirements.
Sarang IP We provide expert legal counsel on intellectual property disputes and high-quality patent drafting.
(Disclaimer: This post is for informational purposes only and does not constitute specific legal advice. Please consult with a professional attorney regarding your specific case.)
