Lead-free frits for plasma displays and other glass devices utilizing glass sealing materials

Abstract

The invention is directed to lead-free glass frit compositions that can be used as sealing frits, the compositions being a blend of: (1) an alkali-ZnO—P 2 O 5 glasses; and (2) at least one cerammed filler material having a crystalline phase selected from the group consisting of beta-quartz, beta-eucryptite, cordierite, and beta-spodumene. The blends of the invention have flow characteristics that enable them to be used at sealing temperatures in the range of 450-550° C., and a CTE value in the range of 60-96×10 −7 /° C.

1 . A lead-free frit seal material comprising a blend of:
 an alkali-ZnO—P 2 O 5  glass comprising, in mol %, of 28-40% P 2 O 5 , 30-40% ZnO, 0-10% Li 2 O, 0-15 Na 2 O, 0-15% K 2 O, 5-25% (Li 2 O+Na 2 O+K 2 O), 0-10% B 2 O 3 , 0-3% Al 2 O 3 , 0-5% WO 3  and 0-5% MoO 3 ; and   at least one filler material having a crystalline phase selected from the group consisting of beta-quartz, beta-eucryptite, cordierite, and beta-spodumene.   
   
   
       2 . The frit sealing material blends according to  claim 1 , wherein said blends have a CTE value in the range of 60−90×10 −7 /° C. 
   
   
       3 . (canceled) 
   
   
       4 . The frit sealing material blend according to  claim 1 , wherein said glass is a alkali-zinc-phosphate glass, and said blend has a composition, in weight percent, of glass in the range of 65-80% and filler in the range of 35-20%. 
   
   
       5 . (canceled) 
   
   
       6 . The frit sealing material blend according to  claim 1 , wherein said glass is a alkali-zinc-phosphate glass, and said blend has a composition, in weight percent, of glass in the range of 70-75% and filler in the range of 25-30%. 
   
   
       7 . The fit sealing material blend according to  claim 1 , wherein after said lead-free frit sealing material blends are used to seal a display glass, the mismatch value between the display glass and the frit material is less than 300 ppm for the frit. 
   
   
       8 . The frit sealing material blends according to  claim 7 , wherein the mismatch value is less than 100 ppm for the frit. 
   
   
       9 . The fit sealing material blend according to  claim 1 , wherein said blend has a particle size distribution d 90  of 90% of particles being 50 μm or smaller. 
   
   
       10 - 14 . (canceled) 
   
   
       15 . A lead-free frit sealing material comprising a blend of:
 an alkali-ZnO—P 2 O 5  glass having a composition, in mol %, of 33-40% P 2 O 5 , 31-38% ZnO, 4-6% Li 2 O, 8-12% Na 2 O, 4-9% K 2 O, 0.5-1.5% Al 2 O 3 , 2-5% B 2 O 3 , 1-3% WO 3  and 1-3% MoO 3 ; and   at least one filler material having a crystalline phase selected from the group consisting of beta-quartz, beta-eucryptite, cordierite, and beta-spodumene.   
   
   
       16 . The blend according to  claim 15 , wherein said blend has a CTE value in the range of 60−90×10 −7 /° C. 
   
   
       17 . The frit sealing material blend according to  claim 15 , wherein said glass is an alkali-zinc-phosphate glass, and said blend has a composition, in weight percent, of glass in the range of 70-75% and filler in the range of 25-30%.