US3644151A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and device for crucible-free zone melting a crystalline rod
Assignee: Siemens AG
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Filing: 1970-03-13
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Granted: 1972-02-22
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Expires: 1990-03-13
Abstract
Abstract Method of crucible-free zone melting a crystalline rod, such as a semiconductor rod especially, wherein the rod is surrounded by an induction heating coil energizable so as to form a molten zone in the rod, includes passing the molten zone axially through the rod, and simultaneously maintaining the crystalline rod and the induction heating coil at the same electric potential during passage of the molten zone through the rod; and device for carrying out the method.
Inventors
- 👤 Wolfgang Keller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 20:04
CPC Classifications
H; H05; H05B; H05B6/00; H05B6/02; H05B6/06; C; C30; C30B; C30B13/00; C30B13/16; C30B13/20; Y; Y10; Y10T; Y10T117/00; Y10T117/10; Y10T117/1024; Y10T117/1076; Y10T117/1088
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
71 words
Device for crucible free zone melting a crystalline rod, such as a semiconductor rod especially, comprising a melting chamber, holders mounted in said chamber for end supporting a crystalline rod to be zone melted, an induction heating coil mounted in said chamber for heating a melting zone in the rod, and means for electrically connecting a middle portion of the induction heating coil to at least one of said rod holders.
Claim 2
Dependent Claim
31 words
Device according to claim 2 wherein at least one of said rod end holders, said middle portion of said induction heating coil and said melting chamber are electrically connected to ground.
Claim 3
Dependent Claim
26 words
Device according to claim 2 wherein said rod end holders and said middle portion of said induction heating coil are electrically insulated from said melting chamber.
Claim 4
Dependent Claim
80 words
Device for crucible-free zone melting a crystalline rod, such as a semiconductor rod especially, comprising a melting chamber, holders mounted in said chamber for end supporting a crystalline rod to be zone melted, an induction heating coil mounted in said chamber for heating a melting zone in the rod, an electrical balancing unit connected in parallel with said induction heating coil, said electrical balancing unit having a central tap electrically connected to at least one of said rod end holders.
Claim 5
Dependent Claim
14 words
Device according to claim 5 wherein said balancing unit is a capacitive divider circuit.
Claim 6
Dependent Claim
14 words
Device according to claim 5 wherein said balancing unit is an inductive divider circuit.
Claim 7
Dependent Claim
65 words
Device according to claim 7 including a high-frequency generator having a tank circuit, and said induction heating coil is connected in a heating circuit with a coupling coil, said heating circuit being inductively coupled by said coupling coil with said tank circuit of said high-frequency Generator, said coupling coil having a middle winding portion electrically connected to at least one of said rod end holders.
Claim 8
Dependent Claim
25 words
Device according to claim 5 wherein said center tap, at least one of said rod end holders and said melting chamber are connected to ground.
Claim 9
Dependent Claim
21 words
Device according to claim 5 wherein said center tap and said rod end holders are electrically insulated from said melting chamber.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-02-21 | 1975-08-23 | 1976-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-21 | 1979-08-23 | 1980-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-21 | 1983-08-23 | 1984-02-22 | $7700.00 | Window Closed / Lapsed |