Enclosure for acoustic insulation of an apparatus contained within said enclosure

Patent metadata

Field	Value
Publication number	US-9453335-B2
Application number	US-201213439539-A
Country	US
Kind code	B2
Filing date	Apr 4, 2012
Priority date	Feb 1, 2006
Publication date	Sep 27, 2016
Grant date	Sep 27, 2016

Abstract

The invention relates to an enclosure with a substantial rectangular configuration, adapted to contain an apparatus sensitive to acoustic vibrations, the enclosure comprising walls and acoustic damping material located within the wall, wherein the acoustic damping material comprises at least one absorbing body of acoustic energy absorbing material located adjacent to a rib of the enclosure. The acoustic vibrations most disturbing the processes in the apparatus within the enclosure are caused by standing acoustic waves within the enclosure with frequencies in the range between 50 Hz and 1000 Hz. These acoustic waves are efficiently damped by the provision of a block of acoustic absorbing material adjacent to one of the ribs of the enclosure, to such an extent that the need for thick walls of the enclosure is substantially obviated, leading to a less voluminous enclosure.

First claim

We claim as follows:

1. An enclosure adapted to contain a particle-optical apparatus sensitive to acoustic vibrations, the enclosure comprising:
walls defining an outer boundary of the enclosure and made of sheet metal with a mass per surface area of between 10 kg/m 2 and 60 kg/m 2 to improve a reflection of acoustic waves from outside the enclosure, the walls including a front wall, a rear wall, side walls, and an upper wall; and
acoustic damping material located within the enclosure, the acoustic damping material comprising at least one absorbing body of acoustic energy absorbing material adapted to dampen standing waves within the enclosure to minimize disturbance of the operation of the particle-optical apparatus.

2. The enclosure as claimed in claim 1 , wherein the enclosure comprises only one absorbing body, the body being located adjacent to a corner of the enclosure.

3. The enclosure as claimed in claim 1 , wherein the absorbing body is located at an upper corner of the enclosure.

4. The enclosure as claimed in claim 1 , wherein the absorbing body is made of mineral wool.

5. The enclosure as claimed in claim 1 , wherein a thickness of the sheet metal is between 0.5 mm and 5 mm.

6. The enclosure as claimed in claim 1 , wherein the enclosure offers space for operating and maneuvering around the particle-optical apparatus.

7. The enclosure as claimed in claim 1 , wherein the at least one absorbing body of acoustic energy absorbing material comprises a rectangular or block-shaped envelope.

8. The enclosure as claimed in claim 7 , wherein a size of at least one side of the rectangular or block-shaped envelope is substantially equal to ¼ of an inner size of the enclosure in a same direction.

9. The enclosure as claimed in claim 1 , wherein the at least one absorbing body is packed in an envelope of flexible material.

10. A method of reducing vibration affecting a particle-optical apparatus sensitive to acoustic vibrations, comprising;
providing an enclosure around a particle-optical apparatus sensitive to acoustic vibrations, wherein an outer boundary of the enclosure is defined by enclosure walls made of sheet metal with a mass per surface area of between 10 kg/m 2 and 60 kg/m 2 to improve a reflection of acoustic waves from outside the enclosure, and wherein the enclosure walls include a front wall, a rear wall, side walls, and an upper wall; and
providing within the enclosure an acoustic damping material including at least one absorbing body of acoustic energy absorbing material adapted to dampen standing waves within the enclosure to minimize disturbance of the operation of the particle-optical apparatus.

11. The method of claim 10 , wherein the enclosure provides enough volume to allow space for operating and maneuvering around the particle-optical apparatus.

12. The method of claim 10 , wherein the at least one absorbing body of acoustic energy absorbing material comprises a rectangular or block-shaped envelope, a size of at least one side of the rectangular or block-shaped envelope is substantially equal to ¼ of an inner size of the enclosure in a same direction.

13. The method of claim 10 in which providing an acoustic damping material includes providing mineral wool.

14. The enclosure as claimed in claim 1 , further comprising a layer of material with a high specific mass to increase the mass per surface area of the walls applied to the enclosure walls.

15. The enclosure as claimed in claim 14 in which the layer of material comprises a layer of bitumen.

16. The enclosure as claimed in claim 14 in which the layer of material with a high specific mass has a thickness approximately twice the thickness of the enclosure walls.

17. The enclosure as claimed in claim 5 , wherein a thickness of the sheet metal is between 0.75 mm and 1.5 mm.

18. The enclosure as claimed in claim 1 wherein the volume of the at least one absorbing body is equal to approximately 1/64 th the volume of the enclosure.

19. The method of claim 16 in which providing an enclosure around the particle-optical apparatus includes providing an enclosure including providing on the enclosure walls a layer of material with a high specific mass to increase the mass per surface area of the enclosure walls.

20. The method of claim 19 in which the layer of material comprises a layer of bitumen.

21. The method of claim 19 in which the layer of material has a thickness approximately twice the thickness of the enclosure walls.

22. The method of claim 10 in which providing an enclosure around the particle-optical apparatus includes providing metal walls with a thickness between 0.75 mm and 1.5 mm.

23. The enclosure as claimed in claim 1 , wherein the particle-optical apparatus is a wafer stepper.

24. The enclosure as claimed in claim 1 , wherein the particle-optical apparatus is an electron microscope.

Assignees

• Visscher Albert
• Schroen Joseph Hubert Marie Guillaume
• Fei Co

Inventors

• Visscher Albert
• Schroen Joseph Hubert Marie Guillaume

Classifications

• E04B1/8218 Primary

  soundproof enclosures · CPC title

• E04B1/8209

  sound absorbing devices (E04B1/8218, E04B1/8227 take precedence) · CPC title