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Verfahren zum Fuegen justierter diskreter optischer Elemente

Joining small, aligned, discrete optical elements for semiconductor- related and medical applications, first adds thin metallic layers then joins elements using solder supplied in pressurized, inert gas flow
 
: Beckert, E.; Banse, H.; Zakel, E.; Fettke, M.

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Frontpage ()

DE 102007002436 A: 20070109
DE 102007002436 A: 20070109
B23K0001
German
Patent, Electronic Publication
Fraunhofer IOF ()

Abstract
(A1) Die Erfindung betrifft ein Verfahren zum Fuegen justierter diskreter optischer Elemente. Es ist dabei Aufgabe der Erfindung, ein Verfahren vorzuschlagen, mit dem optische Elemente im justierten Zustand gefuegt werden koennen, wobei eine thermische und langzeitstabile Verbindung mit geringem Aufwand und hoher Positioniergenauigkeit hergestellt werden kann. Mit dem erfindungsgemaessen Verfahren zum Fuegen justierter diskreter optischer Elemente werden am optischen Element zu fuegende Oberflaechenbereiche mit mindestens einer metallischen Duennschicht versehen, die anschliessend mit einem fluessigen Lot beruehrungslos dosiert benetzt werden. Das flussmittelfreie Lot wird ueber eine Duese mit einem unter Druck stehenden Gasstrom auf die zu fuegenden Oberflaechenbereiche appliziert.

 

WO 2008083676 A1 UPAB: 20080815 NOVELTY - Thin metallic layers are deposited on surface zones of optical elements to be jointed. These are then dosed with liquid solder, whilst avoiding mechanical contact. The solder, free of flux, is delivered in a pressurized, inert gas flow. It is applied to the surface zones to be joined, using a nozzle. The solder is applied into a gap, at the join. Gas flow distributes solder over the zones to be joined. The thin metallic layers are titanium, chromium, gold, tungsten and/or platinum. DETAILED DESCRIPTION - Solder is applied to an upper, thin metallic layer of gold. The solder itself, is a eutectic alloy, i.e. gold-tin, silver-tin, or bismuth-tin. Solder is melted before application, by laser-irradiation. Solder and either a thick- or a thin metallic layer, form intermetallic phases or mixed crystals in a transition region. Solder application is pulsed. During this process, the position of application on the surfaces being joined, is varied. The solder applicator is moved and positioned in three dimensions, under electronic control. USE - To join aligned, discrete optical elements by soldering, for e.g. semiconductor-related or medical application. ADVANTAGE - This process responds to the need for very small optical components, in which the elements must be fixed in position with the highest precision. The assembly has long term stability under varying temperatures and exposure to electromagnetic irradiation. Coated metallic films enhance solder wetting. The method reliably joins transparent elements with critical thermal and mechanical properties. The process is comparatively low in cost, yet precise alignment is achieved. Optical components produced, are used in conjunction with lasers, LED illumination and semiconductor optics. They can be made from biocompatible materials, and are resistant to medical autoclaving.

: http://publica.fraunhofer.de/documents/N-81965.html