Method and apparatus for applying solder to a work piece

Abstract

The invention concerns a method and an apparatus for the application of solder onto a work piece, wherein the solder is soldered on at a soldering temperature T L and subject to the influence of ultrasound. In order to be able to solder without difficulties the solder onto work pieces that exhibit sensitivity to breakage it is proposed that the solder is heated, is applied to the work piece that is supported in particular in a spring-mounted manner, and is soldered-on subject to the influence of ultrasound.

1 - 15 . (canceled) 
     
     
         1 . An apparatus for the application and soldering-on of a solder in a soldering zone onto a work piece, in particular onto a semiconductor component such as a solar cell, encompassing a soldering supply device, a heating device for the solder, an ultrasound sonotrode as well as a transport installation for the transport of the work piece relative to the heating device as well as also the ultrasound sonotrode, wherein
 the transport installation transports the work piece through the soldering zone in a spring-mounted manner by means of the pressing-on of the same in the direction of the ultrasound sonotrode.   
     
     
         2 . An apparatus according to claim  16 , wherein the transport installation features a first and second transport element between which the work piece is fixed in a clamped manner, whereby the first transport element is actively driven and the second transport element is driven by means of frictional engagement with the first transport element or the work piece or by means of its own additional drive. 
     
     
         3 . An apparatus according to claim  17 , wherein the first and the second transport elements are endless flat elements or endless round elements such as flat belts or round sections. 
     
     
         4 . An apparatus according to claim  17 , wherein the first and/or the second transport element features two endless flat elements or endless round elements that are spaced apart to each other and that are guided respectively by guide rollers that originate from a common axis. 
     
     
         5 . An apparatus according to claim  17 , wherein the first transport installation can be driven via a third transport installation, via which the work piece can be delivered to the first and second transport installation. 
     
     
         6 . An apparatus according to claim  16 , wherein the heating device and the ultrasound sonotrode are adjustable as a unit relative to the transport plane of the work piece that is established by the first transport installation. 
     
     
         7 . An apparatus according to claim  16 , wherein the heating device and the ultrasound sonotrode are adjustable relative to one another and to the transport plane. 
     
     
         8 . An apparatus according to claim  16 , wherein the heating device features a discharge opening that releases molten solder and is aligned toward the transport plane. 
     
     
         9 . An apparatus according to claim  23 , wherein the ultrasound sonotrode, with its sonotrode head that contacts the molten solder, is disposed directly in the area of the discharge opening or is spaced apart from it. 
     
     
         10 . An apparatus according to claim  16 , wherein the apparatus features at least one isolated gas supply channel that is isolated against the heating device and from which inert gas can be supplied to the soldering zone. 
     
     
         11 . An apparatus according to claim  16 , wherein the heating device features on the side facing the work piece at least one sliding runner. 
     
     
         12 . An apparatus according to claim  26 , wherein the heating device is supported by means of the at least one sliding runner on the work piece in a sliding manner. 
     
     
         13 . An apparatus according to claim  16 , wherein by means of a sensor the work piece or the solder applied to it is determined and the ultrasound sonotrode can be aligned toward the solder depending on the determined values. 
     
     
         14 . An apparatus according to claim  16 , wherein the area of the ultrasound sonotrode that comes in contact with the solder features a width that is equal to or smaller than the width of a molten soldering strip that is applied onto the work piece. 
     
     
         15 . Apparatus according to claim  16 , wherein the area of the ultrasound sonotrode that comes in contact with the solder features a hard material layer made of tungsten carbide, silicon carbide, boron nitride or diamond.