Optical contact bonding: Difference between revisions
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==History== |
==History== |
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[[Isaac Newton]] has been credited with the first description of totally conformal interaction observed through the interference phenonoma known as [[Newtons rings]], though it was [[S.D. Poisson]] in 1823 who first described the optical characteristics of two identical surfaces in contact. It was not until the 19th Century that objects of such precision were first made that the phenonoma was observed. This clinging together was described as "wringing together", or as "ansprengen" in german. By 1900 optical prisms were being made using optical contact bonding, and the following century saw further research into the phenonoma at the same time as ideas of interatom interactions where first being studied.<ref>Wafer bonding. Marin Alexe, U. Gösele. Page 5 [[http://books.google.co.uk/books?id=egZWYZRjf60C&lpg=PP1&pg=PP1|google books]]</ref> |
[[Isaac Newton]] has been credited with the first description of totally conformal interaction observed through the interference phenonoma known as [[Newtons rings]], though it was [[S.D. Poisson]] in 1823 who first described the optical characteristics of two identical surfaces in contact. It was not until the 19th Century that objects of such precision were first made that the phenonoma was observed. This clinging together was described as "wringing together", or as "ansprengen" in german. By 1900 optical prisms were being made using optical contact bonding, and the following century saw further research into the phenonoma at the same time as ideas of interatom interactions where first being studied.<ref>Wafer bonding. Marin Alexe, U. Gösele. Page 5 [[http://books.google.co.uk/books?id=egZWYZRjf60C&lpg=PP1&pg=PP1 | google books]]</ref> |
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==Explanation== |
==Explanation== |
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Intermolecular forces such as [[Van der Waals forces]], [[hydrogen bonds]], and [[dipole dipole interactions]] are not typically sufficiently strong to hold two apparently conformal rigid bodies together, since the forces drop of rapily with distance<ref>More rapidly than 1/distance<sup>2</sup></ref>, and the actual area in contact between the two bodies is small due to surface roughness, and minor imperfections. |
Intermolecular forces such as [[Van der Waals forces]], [[hydrogen bonds]], and [[dipole dipole interactions]] are not typically sufficiently strong to hold two apparently conformal rigid bodies together, since the forces drop of rapily with distance<ref>More rapidly than 1/distance<sup>2</sup></ref>, and the actual area in contact between the two bodies is small due to surface roughness, and minor imperfections. |
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Revision as of 21:18, 13 July 2009
Optical contact bonding is a glueless process whereby two closely conformal surfaces are joined together, being held purely by intermolecular forces
History
Isaac Newton has been credited with the first description of totally conformal interaction observed through the interference phenonoma known as Newtons rings, though it was S.D. Poisson in 1823 who first described the optical characteristics of two identical surfaces in contact. It was not until the 19th Century that objects of such precision were first made that the phenonoma was observed. This clinging together was described as "wringing together", or as "ansprengen" in german. By 1900 optical prisms were being made using optical contact bonding, and the following century saw further research into the phenonoma at the same time as ideas of interatom interactions where first being studied.[1]
Explanation
Intermolecular forces such as Van der Waals forces, hydrogen bonds, and dipole dipole interactions are not typically sufficiently strong to hold two apparently conformal rigid bodies together, since the forces drop of rapily with distance[2], and the actual area in contact between the two bodies is small due to surface roughness, and minor imperfections.
However if the bodies are conformal to an accuracy of better than 10 angstroms, then a sufficient surface area is is close enough contact for the intermolecular interactions to have an observable real world physical manifestation ie the two objects stick together.[3]
Such a condition requires a high degree of accuracy and surface smoothness, which is typically found in optical components such as prisms.
Production of an optical contact bond
In addition to both surfaces being practically conformal (in practice often completely flat), the surfaces must also be extremely clean and free from any small contamination that would prevent or weaken the bond - including grease films, or specks of dust. For bonding to occur the surfaces only need to be brought together, the intermolecular forces draw the bodies into the lowest energy conformation and no pressure is needed to be applied.
Advantages
Since the method requires no binder, balsam or glue the physical properties of the bound object are the same as the objects joined. Typically glues and binders are more heat sensitive, or have undesirable properties compared to the actual bodies being joined. The use of optical contact binding allows the production of a final product with properties as good as the bulk solid.[4]
Uses
See also
References
- ^ Wafer bonding. Marin Alexe, U. Gösele. Page 5 [| google books]
- ^ More rapidly than 1/distance2
- ^ Design and fabrication of acousto-optic devices. Akis P. Goutzoulis, Dennis R. Pape, Sergeĭ Viktorovich Kulakov page 383 [| google books]
- ^ Optical Contacting: Changing the Interface of Optics. Chris Myatt, Nick Traggis and Kathy Li Dessau. Precision Photonics Corporation precisionphotonics.com