Electrical component having pre-soldered surface with flux reservoirs

Abstract

A pre-soldered pre-fluxed electrical component or connector, which can protect the flux from wearing off the surface of solder during shipping and handling. The electrical component can include a terminal pad. A layer of solder can be on the terminal pad. The layer of solder can have a surface with a series of generally equally spaced apart flux wells formed in the surface of the solder for protectively storing and retaining flux therein. The flux wells can have a lateral dimension of at least 0.05 mm and a depth of at least 0.023 mm that is deep enough for retaining a quantity of flux therein when flux on the surface of the layer of solder wears off during shipping and/or handling.

What is claimed is: 
     
         1 . An electrical component comprising:
 a terminal pad; and   a layer of solder on the terminal pad, the layer of solder having a surface with a series of generally equally spaced apart flux wells formed in the surface of the solder for protectively storing and retaining flux therein, the flux wells having a lateral dimension of at least 0.05 mm.   
     
     
         2 . The electrical component according to  claim 1 , wherein the flux wells have a diameter of at least 0.05 mm, and are in a continuous pattern with at least 0.035 mm spacing in x and y directions. 
     
     
         3 . The electrical component according to  claim 1 , wherein the layer of solder consists essentially of 66% to 90% indium, 4% to 25% tin, 0.5% to 9% silver, 0.1% to 8% antimony, 0.03% to 4% copper, 0.03% to 4% nickel, and 0.2% to 6% zinc by weight. 
     
     
         4 . An electrical component comprising:
 a terminal pad; and   a layer of solder on the terminal pad, the layer of solder having a surface with a knurled pattern formed in the surface of the solder for protectively storing and retaining flux therein.   
     
     
         5 . The electrical component according to  claim 4 , wherein the knurled pattern comprises a first series of generally equally spaced apart elongate indentations. 
     
     
         6 . The electrical component according to  claim 5 , wherein the knurled pattern further comprises a second series of generally equally spaced apart elongate indentations which cross said first series at an angle. 
     
     
         7 . The electrical component according to  claim 4 , wherein the layer of solder consists essentially of 66% to 90% indium, 4% to 25% tin, 0.5% to 9% silver, 0.1% to 8% antimony, 0.03% to 4% copper, 0.03% to 4% nickel, and 0.2% to 6% zinc by weight. 
     
     
         8 . A method of protecting flux on a pre-soldered pre-fluxed electrical component, comprising the steps of:
 providing the electrical component with a terminal pad;   providing a layer of solder on the terminal pad, the layer of solder having a surface; and   providing a layer of flux on the layer of solder, at least portions of the flux filling a series of generally equally spaced apart flux wells formed in the surface of the solder which protectively store and retain flux therein from wear during shipping, the flux wells having a lateral dimension of at least 0.05 mm.   
     
     
         9 . The method according to  claim 8 , further comprising the step of providing the flux wells with a diameter of at least 0.05 mm, and a continuous pattern with at least 0.035 mm spacing in x and y directions. 
     
     
         10 . The method according to  claim 8 , wherein the layer of solder consists essentially of 66% to 90% indium, 4% to 25% tin, 0.5% to 9% silver, 0.1% to 8% antimony, 0.03% to 4% copper, 0.03% to 4% nickel, and 0.2% to 6% zinc by weight. 
     
     
         11 . A method of protecting flux on a pre-soldered pre-fluxed electrical component comprising the steps of:
 providing the electrical component with a terminal pad;   providing a layer of solder on the terminal pad, the layer of solder having a surface;   providing a layer of flux on the layer of solder, at least portions of the flux filling a knurled pattern formed in the surface of the solder which protectively stores and retains flux therein from wear during shipping.   
     
     
         12 . The method according to  claim 11 , further comprising the step of providing the knurled pattern with a first series of generally equally spaced apart elongate indentations. 
     
     
         13 . The method according to  claim 12 , further comprising the step of providing a second series of generally equally spaced apart elongate indentations which cross said first series at an angle. 
     
     
         14 . The method according to  claim 11 , wherein the layer of solder consists essentially of 66% to 90% indium, 4% to 25% tin, 0.5% to 9% silver, 0.1% to 8% antimony, 0.03% to 4% copper, 0.03% to 4% nickel, and 0.2% to 6% zinc by weight. 
     
     
         15 . A method of soldering a pre-soldered pre-fluxed electrical component to a substrate, the electrical component having a terminal pad with a layer of solder on the terminal pad, the layer of solder having a surface, a layer of flux being on the layer of solder, the method comprising the steps of:
 providing a series of generally equally spaced apart flux wells formed in the surface of the solder which protectively store and retain flux therein from wear during shipping and/or handling, the flux wells having a lateral dimension of at least 0.05 mm and a depth of at least 0.023 mm; and   contacting the pre-soldered pre-fluxed terminal pad to the substrate and applying heat, the series of generally equally spaced apart flux wells supplying flux for the soldering operation while spacing a generally even distribution of portions of the solder layer away from heat sink contact with the substrate, providing for even heating and melting of the solder.   
     
     
         16 . The method according to  claim 15 , further comprising the step of providing the flux wells with a diameter of at least 0.05 mm, a depth of at least 0.023 mm, and a continuous pattern with at least 0.035 mm spacing in x and y directions. 
     
     
         17 . The method according to  claim 15 , further comprising the step of providing the flux wells with a diameter of about 0.51 mm, a depth of about 0.25 mm, and a continuous pattern with about 0.89 mm spacing in the x and y directions. 
     
     
         18 . The method according to  claim 15 , further comprising the step of providing interconnected flux wells formed by a grid of crisscrossing grooves in x and y directions about 0.15 mm wide, about 0.15 mm deep, and separated from each about by about 0.25 mm. 
     
     
         19 . The method according to  claim 15 , wherein the layer of solder consists essentially of 66% to 90% indium, 4% to 25% tin, 0.5% to 9% silver, 0.1% to 8% antimony, 0.03% to 4% copper, 0.03% to 4% nickel, and 0.2% to 6% zinc by weight.