Non-lead resistor composition
View Patent ↗A non-lead composition for use as a thick-film resistor paste in electronic applications. The composition comprises particles of Li 2 RuO 3 of diameter between 0.5 and 5 microns and a lead-free frit. The particles have had the lithium at or near primarily the surface of the particle at least partially exchanged for atoms of other metals.
1. A composition comprising particles of Li 2 RuO 3 in which only Li atoms have been exchanged for Al, Ga, K, Ca, Mn, H, Na, Cr, Co, Ni, V, Cu, Zn, or Ti atoms, or a combination thereof.
2. A composition according to claim 1 in which at least 50 mol % of the Li atoms have been exchanged.
3. A composition according to claim 1 in which at least 75 mol % of the Li atoms have been exchanged.
4. A composition according to claim 1 wherein a Li 2 RuO 3 particle comprises first and second layers, and more Li atoms are exchanged in the first layer than in the second layer.
5. A composition according to claim 4 wherein more than 80% of the Li atoms in the first layer are exchanged.
6. A composition according to claim 4 wherein less then 20% of the Li atoms in the second layer are exchanged.
7. A composition according to claim 4 wherein the first and second layers are adjacent.
8. A composition according to claim 1 wherein an atom exchanged for Li has a 2+ valence or a 3+ valence.
9. A composition according to claim 1 wherein an atom exchanged for Li comprises one or more members of the group consisting of Al, Cu, Mg, Zn, Ga, and Mn.
10. A composition according to claim 1 that is described by formula as follows: M +1 x M +2 y M +3 z Li 2-x-2y-3z RuO 3 where (x+2y+3z)≦1.5, and where M is selected from one or more members of the group consisting of Al, Ga, K, Ca, Mn, Na, H, Cr, Co, Ni, V, Cu, Zn, and Ti.
11. A composition according to claim 10 further comprising one or both of an alkali metal, zinc alumino-borosilicate frit, and an alkaline-earth metal, zinc alumino-borosilicate frit.
12. A resistor comprising a composition according to claim 11 .
13. A resistor according to claim 12 that has a sheet resistance of about 100 kilohms per square to about 10 megohms per square, and/or a TCR of ±100 ppm/° C.
14. An electronic device comprising a resistor according to claim 12 .
15. A composition according to claim 1 further comprising one or both of an alkali metal, zinc alumino-borosilicate frit, and an alkaline-earth metal, zinc alumino-borosilicate frit.
16. A resistor comprising a composition according to claim 15 .
17. A resistor according to claim 16 that has a sheet resistance of about 100 kilohms per square to about 10 megohms per square, and/or a TCR of ±100 ppm/° C.
18. An electronic device comprising a resistor according to claim 16 .
19. A composition comprising particles of Li 2 RuO 3 in which Li atoms have been exchanged for Al, Ga, K, Ca, Mn, Fe, H, Na, Cr, Co, Ni, V, Cu, Zn, or Ti atoms, or a combination thereof, wherein a Li 2 RuO 3 particle comprises first and second layers, and more Li atoms are exchanged in the first layer than in the second layer.
20. A composition according to claim 19 in which at least 50 mol % of the Li atoms have been exchanged.
21. A composition according to claim 19 wherein more than 80% of the Li atoms in the first layer are exchanged.
22. A composition according to claim 19 wherein less than 20% of the Li atoms in the second layer are exchanged.
23. A composition according to claim 19 wherein the first and second layers are adjacent.
24. A composition according to claim 19 further comprising one or both of an alkali metal, zinc alumino-borosilicate frit, and an alkaline-earth metal, zinc alumino-borosilicate frit.
25. A resistor comprising a composition according to claim 24 .
26. An electronic device comprising a resistor according to claim 25 .