Claims
- 1. A method of removing B.sub.2 O.sub.3 encapsulant from a structure comprising the steps of:
- (a) providing a structure having a melting temperature above 400.degree. C. and having a layer of B.sub.2 O.sub.3 thereon;
- (b) placing said structure with said layer of B.sub.2 O.sub.3 thereon in a chamber at a temperature in excess of 400.degree. C. and below said melting temperature of said structure and at a pressure above the foaming temperature of said B.sub.2 O.sub.3 ;
- (c) decreasing said pressure in said chamber until said B.sub.2 O.sub.3 foams;
- (d) then lowering the temperature in said chamber to below 400.degree. C.;
- (e) washing said structure with said B.sub.2 O.sub.3 thereon in an alcohol after said B.sub.2 O.sub.3 has foamed; and
- (f) then washing said structure with said B.sub.2 O.sub.3 thereon after said B.sub.2 O.sub.3 has foamed in a liquid non-reactive with said structure to remove said B.sub.2 O.sub.3 from said structure.
- 2. The method of claim 1 wherein said pressure is lowered to about -14.7 psig.
- 3. The method of claim 1 wherein said temperature is lowered to about ambient temperature external of said chamber.
- 4. The method of claim 3 wherein said alcohol is one of methanol and isopropanol.
- 5. The method of claim 2 wherein said temperature is lowered to about ambient temperature external of said chamber.
- 6. The method of claim 5 wherein said alcohol is one of methanol and isopropanol.
- 7. The method of claim 6 wherein said liquid is water.
- 8. The method of claim 1 wherein said alcohol is one of methanol and isopropanol.
- 9. The method of claim 2 wherein said alcohol is one of methanol and isopropanol.
- 10. The method of claim 1 wherein said liquid is water.
Parent Case Info
This is a divisional of application Ser. No. 07/748,602 filed Aug. 22, 1991 now abandoned.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
4589898 |
Beaver |
May 1986 |
|
4773852 |
Tanji et al. |
Sep 1988 |
|
Divisions (1)
|
Number |
Date |
Country |
Parent |
748602 |
Aug 1991 |
|