T 1573/12 - Essential features

Key points

• The Examining Division insisted that a particular thickness range should be included in claim 1, the feature being considered essential. The Board does not agree. 
• The Board however does not simply note that the range is mentioned expressly as "preferably" , but cites the remark in the application that " ..by proper selection of the width of the etch-resist in combination with the thickness of the temporary substrate, the current crack-preventing properties can be regulated"

EPO T 1573/12 - link

Reasons for the Decision

4. Claims (Article 84 EPC 1973)

4.1 In its communication of 27 October 2011, the examining division considered that claim 1 then on file was not clear because an essential feature of the claimed invention was missing(see point 5). Although the current version of claim 1 is different from the one on file at that time, the objection would still apply to current claim 1 and, therefore, the board considers it appropriate to address it.

4.2 The examining division considered that the range of the thickness of the temporary substrate foil should have been mentioned in claim 1. Making reference to the statements in lines 5-13 on page 9 of the description, the examining division stated that the thickness range of 1 - 200 mym of the temporary substrate foil mentioned therein was an essential feature of the invention, since it was required (page 9, line 5) that the temporary substrate foil had a certain thickness to ensure sufficient support for the foil during its manufacturing process. The omission of this essential feature was contrary to the requirements of Article 84 EPC.

4.3 The board does not share the examining division's conclusion on this matter.

In the introductory passage describing the temporary substrate (foil) - page 7, line 30 - page 8, line 6 - a series of conditions the temporary substrate foil has to meet are enumerated, concluding that "The person skilled in the art will be able to select a suitable temporary substrate within these guidelines" (page 8, lines 5 and 6).

Regarding the thickness of the temporary substrate (foil) the application mentions several possibilities. In the relevant passage (page 9, lines 7-13), it is stated that the thickness is generally not required to be more than 500 mym. Then it is stated that the thickness is preferably 1-200 mym and, ultimately, that a thickness of 5-150 mym, or more particularly of 10-100 mym is preferred. Finally, in the following paragraph, it is stated that "...by proper selection of the width of the etch-resist in combination with the thickness of the temporary substrate, the current crack-preventing properties can be regulated." (page 9, lines 14-16). These passages lead to the conclusion that a specific value of the thickness of the temporary substrate foil is not considered to be an essential feature of the claimed invention; rather, the selection of a thickness value for the temporary substrate foil depends on other parameters as well and is considered to be within the skilled person's common general knowledge.

Hence, there are no essential features of the invention missing from the claims. The board is also satisfied that the other requirements of Article 84 EPC 1973 are met.