February, 2018｜News Letter

1. How should Effect of Claimed Invention at issue be Compared to that of Invention Disclosed in Prior Art Reference?

Senju Metal Industry Co., Ltd. v. Harima Chemicals, Inc., Case No. 2017 (Gyo-Ke) 10121 (Decision rendered on February 14, 2018)

The Patentee, Harima Chemicals obtained a patent relating to a solder alloy in 2015. Against all of Claims 1 to 8 of the Harima’s patent, Senju Metal Industry filed an invalidation trial with the JPO in 2016. The JPO dismissed the Senju’s demand in 2017. Senju filed an appeal against the JPO's decision to the IPHC in 2017.

Claims 1 and 2 of the Harima’s patent at issue claims as follows:
1. A solder alloy consisting essentially of tin, silver, copper, bismuth, antimony, and cobalt,
wherein relative to a total amount of the solder alloy,
the silver content is 2 mass% or more and 4 mass% or less,
the copper content is 0.3 mass% or more and 1 mass% or less,
the bismuth content is more than 4.8 mass% and 10 mass% or less,
the antimony content is 3 mass% or more and 10 mass% or less,
the cobalt content is 0.001 mass% or more and 0.3 mass% or less, and
the tin content is the remaining portion.

2. The solder alloy according to claim 1, further containing at least one element selected from the group consisting of nickel, indium, gallium, germanium, and phosphorus, wherein relative to a total amount of the solder alloy, more than 0 mass% and 1 mass% or less of the element is contained.

One of the main issues in this case related to how the effect of the claimed invention at issue should be compared to that of the invention disclosed in a prior art reference. The IPHC answered to the issue as follows:

In the JPO’s decision, the JPO found that there was at least one difference (Difference 2) between the inventions claimed in Claims 2 to 8 of the patent at issue and the inventions disclosed in prior art reference 1 (p.a.r. 1), namely that the former specified “the bismuth content is more than 4.8 mass% and 10 mass% or less”, while the latter disclosed “Bi: 3.2 mass%”. The JPO made the decision on Difference 2 as follows:

The problem to be solved by the inventions claimed in claims 2 to 8 of the patent at issue was to improve the resistance to shock such as dropping vibration after soldering with a lead-free solder alloy and to keep the shock resistance even under exposure to relatively severe temperature cycle conditions. The working examples of the patent at issue showed that the claimed feature of “the bismuth content is more than 4.8 mass% and 10 mass% or less” contributed to solve the above problem. On the other hand, p.a.r. 1 did not evaluate the resistance to shock by drop. Therefore, those skilled in the art could not easily expect the effect of improving the residence to shock by drop by increasing the Bi content of 3.2 mass%, which was already in the preferable range, to 4.8 mass%, although p.a.r. 1 stated that “Bi is added to the solder alloy of the invention in an amount of preferably 1.5 to 5.5 mass%, more preferably 3 to 5 mass%, and even more preferably 3.2 to 5.0 mass%”.

However, the IPHC overturned the above JPO’s decision for reasons stated below:

P.a.r.1 stated that “[i]n the solder alloy of the invention, the temperature cycle characteristics can be further improved by adding Bi”, and that “Bi is added to the solder alloy of the invention in an amount of preferably 1.5 to 5.5 mass%”. This statement motivated to change the Bi content in the inventions disclosed in p.a.r. 1 to a range of more than 4.8 mass% and 5.5 mass% or less, which was in the above preferred range.
The effect of the inventions disclosed in p.a.r. 1 by specifying the Bi content in the above preferred range was to improve the temperature cycle property. The temperature cycle property is a property that “even if a temperature cycle test in a range from -40℃ to +125℃ is repeated for around 3,000 cycles, solder joint portions having a very small amount of solder also do not have cracks. In addition, even in a case where a crack occurred, the crack is prevented from propagating in the solder”. When no cracks occurred in the solder joint portions after a temperature cycle test and the effect of preventing the cracks from propagating was improved, the shock resistance under the severe temperature cycle conditions was also improved. Further, when the shock resistance under the severe temperature cycle conditions was improved, it was expected that the shock resistance not under such severe temperature cycle conditions was also high. Therefore, the effect of the inventions claimed in Claims 2 to 8 specifying the Bi content was not remarkable compared to the effect of the inventions disclosed in p.a.r. 1 specifying the Bi content in the range of more than 4.8 mass% and 5.5 mass% or less. Accordingly, those skilled in the art could have easily conceived of changing the numerical value of “Bi: 3.2 mass%” in the inventions disclosed in p.a.r. 1 to the range of “more than 4.8 mass% and 5.5 mass% or less”.

Conclusively, the IPHC upheld the Senju’s appeal on Claims 2 to 8, and cancelled the JPO’s decision on Claims 2 to 8.

An appeal to the Supreme Court was filed against this decision, and thus the decision is NOT final and binding.

K&P’s Comments A remarkable effect over the prior art is one of the important factors for examining inventive step under the Japanese patent practice. As seen from the above IPHC decision, even if the effect of the claimed invention at issue does not seem to be the same as that of the invention disclosed in a prior art reference, the inventive step of the claimed invention may be denied if it can be shown that the former effect is closely related to the latter effect, and it is expected from the latter that the former is not remarkable.

(by Katsumasa OSAKI, Patent Attorney)

In February 2018, the IPHC handed down 14 decisions including the above case on patent, and overturned the previous decisions in 3 cases.

In February 2018, the IPHC handed down 3 decisions on trademark, and overturned the previous decision in 1 case.

In February 2018, the IPHC handed down 1 decision on industrial design, which maintained the previous decision.