T 0036/12 15-07-2014

Summary of Facts and Submissions

I. By its interlocutory decision posted on 17 October 2011 the opposition division decided that, account being taken of the amendments made during the opposition proceedings, European patent No. 1 366 203 in the version according to auxiliary request 1 then on file and the invention to which it relates met the requirements of the EPC.

II. Appellant 1 (patent proprietor) lodged an appeal against that decision on 23 December 2011, paying the appeal fee at the same time. The statement of grounds of appeal was filed on 27 February 2012.

Appellant 2 (opponent) lodged an appeal on 22 December 2011, paying the appeal fee at the same time. The statement of grounds of appeal was filed on 27 February 2012.

III. Oral proceedings before the Board of Appeal were held on 15 July 2014.

IV. Appellant 1 requested that the decision under appeal be set aside and the patent be maintained as granted or on the basis of one of the auxiliary requests 1 to 4 all filed with letter of 27 February 2012 or auxiliary request 5 filed with letter of 13 June 2014 or auxiliary request 6 filed at the oral proceedings.

Appellant 2 requested that the decision under appeal be set aside and the patent be revoked.

V. The independent claims of the patent as granted (main request) read as follows:

"1. A refractory metal plate comprising a thickness, a center, and an edge, the metal being selected from the group consisting of tantalum and niobium, said metal being of at least 99.99% purity, the plate having a grain size of less than about 40 microns and a texture that is uniform both through said thickness and from said center to said edge, and further wherein said refractory metal plate has

i) a constant mix of grains with orientation {100} and {111} crystallographic orientations, and

ii) a distribution of {100} and {111} crystallographic orientations that varies by less than 30 percent across the surface of any plane of said refractory metal plate, said planes being selected from planes that are orthogonal to the thickness of said refractory metal plate, and planes that are diagonal to the thickness of said refractory metal plate, and

iii) a distribution of {100} and {111} crystallographic orientations that varies by less than 30 percent across any thickness of said refractory metal plate."

"5. A process for producing a refractory metal plate wherein the metal comprises a metal selected from the group consisting of tantalum, alloys of tantalum, niobium, alloys of niobium, said metal being of at least 99.99% purity, with fine metallurgical structure and uniform texture comprising:

a) providing a refractory metal starting piece;

b) first reducing the length of the refractory metal starting piece to form a first workpiece by forging the billet to a desired billet thickness with about 35% to 50% reduction; [first forging 14]

c) recrystallization annealing the first workpiece at a first temperature of at least 1370°C;

d) second reducing the diameter of the first workpiece (draw back forging) to a diameter substantially the same as a diameter of the refractory metal starting piece to form a second workpiece;

e) recrystallization annealing the second workpiece at a second temperature of at least 875°C;

f) repeating steps b) to e) as necessary to achieve desired grain structure and texture uniformity;

g) third reducing the second workpiece to a first thickness to form a first plate;

h) fourth reducing the first thickness of the first plate by cross rolling to a second thickness to form a second plate; and

i) recrystallization annealing the second plate at a temperature of at least 875°C."

"9. Use of the metal plate prepared by the process of any of claims 5 to 8 as a sputtering target."

Auxiliary request 1 differs from the main request by the deletion of claim 9 and of the terms "alloys of niobium" and "alloys of tantalum" in dependent claims 3 and 8.

Auxiliary request 2 corresponds to the main request underlying the decision under appeal and differs from auxiliary request 1 in that claim 1 and its dependent claims are directed to

"A sputtering target comprising a refractory metal plate ...".

Auxiliary request 3 corresponds to auxiliary request 1 underlying the decision under appeal and differs from auxiliary request 2 in that it is restricted to the method claims.

Claim 1 of auxiliary request 4 reads as follows (differences in respect of claim 1 of auxiliary request 3 emphasised):

"1. A process for producing a refractory metal plate wherein the metal comprises a metal selected from the group consisting of tantalum, alloys of tantalum, niobium, alloys of niobium, said metal being of at least 99.99% purity, with fine metallurgical structure and uniform texture comprising:

a) providing a refractory metal starting piece of at least 99.99% purity;

b) first reducing the length of the refractory metal starting piece to form a first workpiece by forging the billet to a desired billet thickness with about 35% to 50% reduction; [first forging 14]

c) recrystallization annealing the first workpiece in a vacuum or inert gas at a first temperature of at least 1370°C;

d) second reducing the diameter of the first workpiece (draw back forging) to a diameter substantially the same as a diameter of the refractory metal starting piece to form a second workpiece;

e) recrystallization annealing the second workpiece in a vacuum or inert gas at a second temperature of at least 875°C;

f) repeating steps b) to e) at least one time to achieve desired grain structure and texture uniformity;

g) third reducing the second workpiece to a first thickness to form a first plate;

h) fourth reducing the first thickness of the first plate by cross rolling to a second thickness to form a second plate; and

i) recrystallization annealing the second plate in a vacuum or inert gas at a temperature of at least 875°C."

Claim 1 of auxiliary request 5 reads as follows:

"1. A process for producing a refractory metal plate wherein the metal comprises a metal selected from the group consisting of tantalum, niobium, said metal being of at least 99.99% purity, with fine metallurgical structure and uniform texture comprising:

a) providing a refractory metal starting piece of at least 99.99% purity;

b) first reducing the length of the refractory metal starting piece to form a first workpiece by forging the billet to a desired billet thickness with about 35% to 50% reduction; [first forging 14]

c) recrystallization annealing the first workpiece in a vacuum or inert gas at a first temperature of at least 1370°C;

d) second reducing the diameter of the first workpiece (draw back forging) to a diameter substantially the same as a diameter of the refractory metal starting piece to form a second workpiece;

e) recrystallization annealing the second workpiece in a vacuum or inert gas at a second temperature of at least 875°C;

f) repeating steps b) to e) at least one time to achieve desired grain structure and texture uniformity;

g) third reducing the second workpiece to a first thickness to form a first plate;

h) fourth reducing the first thickness of the first plate by cross rolling to a second thickness to form a second plate; and

i) recrystallization annealing the second plate in a vacuum or inert gas at a temperature of at least 875°C."

Claim 1 of auxiliary request 6 reads as follows:

"1. A process for producing a refractory metal plate wherein the metal consists of tantalum or niobium, said metal being of at least 99.99% purity, with fine metallurgical structure and uniform texture comprising:

a) providing a refractory metal starting piece of at least 99.99% purity;

b) first reducing the length of the refractory metal starting piece to form a first workpiece by forging the billet to a desired billet thickness with about 35% to 50% reduction; [first forging 14]

c) recrystallization annealing the first workpiece in a vacuum or inert gas at a first temperature of at least 1370°C;

d) second reducing the diameter of the first workpiece (draw back forging) to a diameter substantially the same as a diameter of the refractory metal starting piece to form a second workpiece;

e) recrystallization annealing the second workpiece at a second temperature of at least 875°C;

f) repeating steps b) to e) at least one time to achieve desired grain structure and texture uniformity;

g) third reducing the second workpiece to a first thickness to form a first plate;

h) fourth reducing the first thickness of the first plate by cross rolling to a second thickness to form a second plate; and

i) recrystallization annealing the second plate in a vacuum or inert gas at a temperature of at least 875°C."

VI. The arguments of appellant 1 can be summarised as follows:

Main request and auxiliary request 1

It was true that the main request underlying the decision under appeal was more restricted than the present main request (patent as granted) and auxiliary request 1. However, as discussed in numerous decisions and in particular in decision T 386/04 withdrawal of subject-matter and defending the patent with a more restricted claim set did not necessarily mean that said subject-matter had been formally abandoned. Hence, the main request and auxiliary request 1 were admissible.

Auxiliary requests 2 to 4

As disclosed in paragraph [0002], the metal plate of the claimed invention was to be used in the production of a thin film for a variety of applications. The person skilled in the art would know, once given the application of the thin film, which elements were to be considered alloying elements and which not. Hence, he would know how to realise alloys of Ta or Nb with a purity of at least 99.99%, as required by the independent method claim of auxiliary requests 2 to 4. Therefore, the invention claimed in these method claims were sufficiently disclosed.

Auxiliary requests 5 and 6

Claim 1 of auxiliary requests 5 and 6 was based on claim 5 of the patent as granted with some minor amendments. Hence, these requests should be admitted into the proceedings.

Moreover, the step recited in the method claims of these requests of first reducing the length of the refractory metal starting piece to form a first workpiece by forging the billet to a desired billet thickness with about 35% to 50% reduction was disclosed in claims 13 and 19 and on page 7 of the application as originally filed. Therefore, auxiliary requests 5 and 6 did not comprise subject-matter which extended beyond the content of the application as filed.

VII. The arguments of appellant 2 can be summarised as follows:

Main request and auxiliary request 1

Neither the main request nor auxiliary request 1 was

the object of the decision under appeal. Therefore, they should not be admitted into the proceedings.

Auxiliary requests 2 to 4

In auxiliary requests 2 to 4 the independent method claim mentioned alloys of tantalum or niobium of at least 99.99% purity. However, neither the claims, which related to method for the production of a refractory metal plate, nor the description defined on which basis the purity was to be calculated, because they did not specify which elements were alloying elements and which elements were impurities.

Therefore, the patent in suit did not disclose the invention claimed in the independent method claim of each of the auxiliary requests 2 to 4 in a manner sufficiently clear and complete for it to be carried out by a person skilled in the art.

Auxiliary requests 5 and 6

Auxiliary requests 5 and 6 were late-filed without a good reason and prima facie not allowable. Hence, they should not be admitted into the proceedings.

In any event, the step of first reducing the length of the refractory metal starting piece to form a first workpiece by forging the billet to a desired billet thickness with about 35% to 50% reduction, comprised in claim 1 of both auxiliary requests 5 and 6, was not disclosed in the application as originally filed. Therefore, these requests did not comply with the requirements of Article 123(2) EPC.