Gudeng v. Entegris: court emphasized comparison of asserted patent with accused product in infringement analysis

Gudeng Precision Industrial Co., Ltd., a Taiwan-based semiconductor manufacturing system supplier, is the owner of Taiwan invention patent I238804 titled “A filling device for transfer box”, which provides an improved filling valve installable onto a transfer box in the SMIF production line. Engaging in direct competition in the same business of mask handling, Entegris Inc. from the USA was the provider of the FOUP product model A300 and the EUV pod product model EUV 1010 series. The FOUP is a type of plastic carrier designed to securely hold wafers in a controlled environment during transfer, while the EUV pod is a device that safeguards the shipping and transportation of EUV reticles.

At some point in 2021, Gudeng sent a warning letter to Entegris asserting that Entegris’ aforementioned FOUP and EUV pod (“accused products”) infringed Claims 1, 4, 5, 8 and 9 of Gudeng’s ‘804 patent. On November 5, 2021- following receipt of the warning letter from Gudeng - Entegris filed a declaratory suit stating non-infringement together with Gudeng’s lack of legitimate entitlement to both injunction and damages.[1] In response, Gudeng swiftly filed an infringement suit against Entegris on November 30, 2021.[2] Notably, the declaratory suit was instituted first and could not bar the later filing of an infringement suit (this is not the case in the reverse order of filings).

In the infringement analysis, as is the usual practice, the court performed a construction of the patent claims and disassembly of the accused product. By comparing and contrasting the corresponding elements - as shown in the table below for independent Claim 1 - the court found that Claim 1 failed to read on the accused product for at least the different features in bold face that exist only in either Claim 1 or the accused product. Under the all-elements rule, Claim 1 was determined not to have been infringed. Likewise, for independent Claim 9, not all of the technical features deconstructed were the same; therefore, the accused product did not fall within the literal scope of Claim 9. Since Claim 1 was not read on, Claims 4, 5 and 8 depending from Claim 1 were also found not to have been infringed.

Since no literal infringement was found, the plaintiff Gudeng relentlessly alleged equivalent infringement. The court reasoned in the first place that an accused product infringes on a claim under the doctrine of equivalence when the equivalent element of the product performs substantially the same function in substantially the same way to yield substantially the same result as the corresponding element recited in the claim. In the court’s finding, elements 1b – 1e were not equivalent to elements 1B – 1E. For one thing, the accused product did not use a slope structure to guide the motion of an inflatable tube. Instead, the accused product employed a spring to actuate a valve in order to carry out the activity of gas filling. Furthermore, the filling device of the accused product was not entirely made of rubber. Thus, the technical ways between the claimed invention and accused products were substantially different that was not easy to be conceivably replaceable or transformable. For another thing, the absence of a spring in the claimed invention effectively prevents generation of material scraps by reducing friction. It facilitates the maintaining of cleanliness inside the transfer box. Moreover, the use of rubber to make the filling device as claimed not only reduces manufacturing costs but improves the efficiency of processing when necessary. These functions and results were not substantially the same as those of the accused product. To briefly conclude, infringement under the doctrine of equivalents was not constituted.

The plaintiff Gudeng attempted to further argue that the accused product was identical to the defendant Entegris’s patent I423451. Specifically, Figure 6 of the ‘451 patent is a mirror drawing embodying the accused product. The ‘451 patent could be utilized for comparison against the claims of Gudeng’s ‘804 patent, Gudeng persisted. The court rejected Gudeng’s argument. As the court emphasized, what were subject to comparison in an infringement analysis were only the asserting patent claims and the accused product rather than a patented product versus an accused product or patent claims versus another patent. In the present case, the defendant Entegris’s accused product was available to the court, despite there being restricted access due to a secret protection order. The tangible product was legitimate to serve for infringement analysis. Gudeng’s demand for comparing the ‘451 patent of Entegris with its own ‘804 patent was not lawful.

To conclude, the court found no literal or equivalent infringement of Entegris’ accused product. Gudeng’s damages claim of TWD 100 million was dismissed. The case remained appealable.

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