Yangtze Memory Technologies Co Ltd v Micron Technology Inc & Anor

In patent case management, the issues for trial should address the pleaded legal questions, rather than an unpleaded decision to seek patent protection. Model D disclosure is not the default where it risks a broad and burdensome inquiry; targeted Model C disclosure may be proportionate if suitable custodians can cover relevant communications. Earlier patent amendment applications may be required where defining the amendments sooner matters and the claimant has enough information to formulate them. A later application to make reasonable adjustments may remain available where supported by reasonable grounds.

Yangtze Memory Technologies Co Ltd (YMTC), the claimant, and Micron Technology Inc and Micron Europe Ltd, the defendants, were parties to patent proceedings involving EP660 and related patents. At a second case management conference, they disputed the wording of the trial issues and the scope of disclosure into whether information relevant to the inventive concept had passed from former employees to people at YMTC. They also disputed when YMTC should apply for permission to amend the patents. The court considered those case-management issues.

The court resolved the disputed issues and gave case-management directions.

1. List of issues. The court held that issue 1(g), as originally drafted, was inappropriate. The decision to seek patent protection was not the legal question and did not appear on the pleadings; the relevant question concerned who made the invention. The parties’ agreed revisions instead focused issue 1(e) on contact concerning the inventive concept and issue 1(f) on how YMTC developed and arrived at it.
2. Disclosure. The court did not finally decide whether Model C or Model D disclosure should be ordered, and left the question of custodians for further consideration. It gave guidance that Model D was not the default and was very unlikely to be appropriate if it produced a roving inquiry across large parts of YMTC’s business. The court was strongly inclined towards Model C, with suitable custodians, including higher or line managers, and relevant inbound or outbound email concerning the accused characteristics. Micron could renew its argument for Model D if YMTC failed to engage meaningfully on custodians.
3. Patent amendments. The court preferred Micron’s earlier proposed deadlines because the scope of any amendments could significantly affect the proceedings and should be known as soon as possible. YMTC’s amendments in parallel foreign proceedings gave the court confidence that it had enough information to formulate amendments by those dates. Later applications to make reasonable adjustments remained possible; the court considered that a reasonable application supported by reasonable grounds should succeed. The court ordered the dates shown in paragraphs 11(i) and (ii) of the draft order.