Aluminum based solderable contact
View Patent ↗A method of producing a solderable aluminum contact comprises formulating an ink, applying the ink to an aluminum substrate to form an ink layer on a surface of the aluminum substrate, and melting the ink layer. The ink includes a solderable element that is conductive. The melting of the ink layer forms an alloy on the surface of the aluminum substrate including the solderable element.
1. A method of producing a solderable aluminum contact, comprising:
formulating an ink that includes a solderable element that is conductive;
applying the ink to an aluminum substrate to form an ink layer on a surface of the aluminum substrate;
melting the ink layer with an energetic beam to form an alloy on the surface of the aluminum substrate including the solderable element, a beam power of the energetic beam is selected to burn away a thermoplastic material within the ink and break down an oxide layer on the aluminum substrate such that the oxide layer is no longer a macroscopically continuous layer; and
cutting the aluminum substrate and the alloy into a plurality of individual contacts.
2. The method of claim 1 , wherein the solderable element includes an element selected from the group consisting of: tin, silver, zinc, copper, magnesium, palladium, and nickel.
3. The method of claim 1 , wherein the applying step is conducted via a printing process.
4. The method of claim 1 , wherein the applying step is performed within a vacuum chamber or in an inert gas atmosphere.
5. The method of claim 1 , wherein the ink includes a flux material adapted to minimize the formation of an oxide layer on the aluminum substrate or adapted to break down an existing oxide layer on the aluminum substrate during melting.
6. The method of claim 1 , wherein the solderable element facilitates soldering of the solderable aluminum contact with a solderable material.
7. A method of forming a joint between an aluminum contact and a second substrate, comprising:
formulating an ink that includes a solderable element that is conductive;
applying the ink to an aluminum substrate to form an ink layer on a surface of the aluminum substrate;
melting the ink layer with an energetic beam to form a joint contact area including an alloy on the surface of the aluminum substrate, the alloy including the solderable element, a beam power of the energetic beam is selected to burn away a thermoplastic material within the ink and break down an oxide layer on the aluminum substrate such that the oxide layer is no longer a macroscopically continuous layer;
roughening the joint contact area after the formation of the alloy;
cutting the aluminum substrate and the alloy including the roughened joint contact area to form a contact;
applying a conductive adhesive or a solder paste to the joint contact area of the contact;
placing the second substrate on the conductive adhesive or the solder paste; and
heating the conductive adhesive or the solder paste to form the joint between the aluminum contact and the second substrate.
8. The method of claim 7 , wherein the solderable element includes an element selected from the group consisting of: tin, silver, zinc, copper, magnesium, palladium, and nickel.
9. The method of claim 7 , wherein the applying step is conducted via a printing process.
10. The method of claim 7 , wherein the second substrate includes one of: copper, aluminum, tin, gold, nickel plated copper, silver plated copper, a silver plated polymeric material, a gold plated polymeric material, and a combination thereof.
11. The method of claim 7 , wherein the conductive adhesive is selected from the group consisting of: epoxy, cyanoacrylate, polyurethane, acrylic, or silicone with filler materials including silver, tin, copper, gold, nickel, or a combination thereof.
12. The method of claim 7 , wherein the solder paste is selected from the group consisting of: SnPb, SnSb, SnBi, SnCuAg, SnCuNi, SnCu, SnAg, SnZn, SnAgPb, SnAgSb, SnIn, AuGe, and AuIn.
13. The method of claim 7 , wherein the joint is a fluxless joint.
14. The method of claim 7 , wherein a joint resistance between the alloy and the second substrate is at least 75 percent less than a joint resistance between a pristine aluminum and the second substrate.
15. The method of claim 7 , wherein the step of roughening the joint contact area comprises melting the alloy via an energetic beam.
16. The method of claim 1 , wherein a voltage-penetration depth of the energetic beam is adjusted according to the equation:
6.7
×
1
0
-
7
×
V
5
/
3
[
V
]
ρ
[
g/cc
]
wherein V is voltage and p is density of the ink layer.
17. The method of claim 1 , further comprising the steps of:
mechanically removing oxidation from the aluminum substrate prior to the step of applying the ink; and
roughening the alloy on the surface of the aluminum substrate prior to the step of cutting of the aluminum substrate.
18. A method of producing a solderable aluminum contact, comprising:
formulating an ink that includes a solderable element that is conductive;
applying the ink to an aluminum substrate to form an ink layer on a surface of the aluminum substrate;
melting the ink layer with an energetic beam to form an alloy on the surface of the aluminum substrate including the solderable element, a voltage-penetration depth of the energetic beam is adjusted according to the equation:
6.7
×
1
0
-
7
×
V
5
/
3
[
V
]
ρ
[
g/cc
]
wherein V is voltage and p is density of the ink layer; and
cutting the aluminum substrate and the alloy into a plurality of individual contacts.