Method for selectively pretinning a guidewire core

Abstract

A method of pretinning a core wire for a guidewire having an elongate axis, comprising placing a ball of solder within a pocket in a soldering block; melting the ball of solder; holding a core wire over the ball of solder, with the elongate axis in a horizontal orientation; lowering a portion of the core wire into the ball of solder while maintaining the elongate axis in a horizontal orientation; removing the core wire from the ball of solder.

We claim: 
     
         1 . A method of pretinning a core wire for a guidewire having an elongate axis, comprising: placing a ball of solder within a pocket in a soldering block; melting the ball of solder; holding a core wire over the ball of solder, with the elongate axis in a horizontal orientation; lowering a portion of the core wire into the ball of solder while maintaining the elongate axis in a horizontal orientation; removing the core wire from the ball of solder. 
     
     
         2 . The method of  claim 1 , further including, advancing a sponge, soaked in a flux, into contact with the core wire before lowering the core wire into the ball of solder. 
     
     
         3 . The method of  claim 2 , wherein advancing a sponge soaked in a flux into contact with the core wire includes rotating the core wire about the elongate axis. 
     
     
         4 . The method of  claim 2 , wherein advancing a sponge soaked in flux includes advancing a sponge mounted on a jig. 
     
     
         5 . The method of  claim 4 , further including retracting the sponge from the core wire after advancing the sponge. 
     
     
         6 . The method of  claim 1 , wherein lowering a portion of the core wire into the ball of solder includes rotating the core wire about the elongate axis. 
     
     
         7 . The method of  claim 1 , wherein removing the core wire from the ball of solder includes moving the core wire in a direction having a vector component along the elongate axis and a vector component vertically, perpendicular to the elongate axis. 
     
     
         8 . The method of  claim 7 , wherein a ratio of the vector component along the elongate axis to the vector component perpendicular to the elongate axis is in a range of between 2.5 to 3.5. 
     
     
         9 . The method of  claim 1 , wherein placing a ball of solder in a pocket includes placing a ball of solder which is a 80Au/20Sn eutectic solder alloy. 
     
     
         10 . The method of  claim 1 , wherein placing a ball of solder in a pocket includes placing a ball of solder which is in a range of 2 mm to 5 mm in diameter. 
     
     
         11 . The method of  claim 1 , including repeating the steps of lowering the core wire into the ball of solder and then removing the guidewire from the ball of solder between three to five times. 
     
     
         12 . The method of  claim 1 , wherein placing a ball of solder in a pocket in a soldering block includes providing a soldering block comprising commercially pure titanium. 
     
     
         13 . The method of  claim 1 , wherein lowering a portion of the core wire into the ball of solder includes lowering a portion of the core wire that is located between 2 cm and 4 cm from a distal tip of the guidewire core into the ball of solder.