US3727667A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Single set-up sequential heat process for making diamond heat sinks
Assignee: Individual
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Filing: 1971-11-30
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Granted: 1973-04-17
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Expires: 1991-11-30
Abstract
Abstract A multiple-cavity mold with vertical cavities receives a layered ''''stack'''' in each cavity. The stack or charge includes a diamond crystal, a brazing metal alloy and a casting metal slug all of which are impinged upon by a tungsten rod which may or may not become a part of the final stack assembly. The mold is evacuated and the contents heated in temperature stages or steps such that the brazing alloy melts before the casting slug. The temperature is then diminished at a rate to anneal the casting metal in the assembly. Preferably the brazing alloy is a combination of a transitional metal with a noble metal. The casting metal is of a superior heat-conducting material, such as copper or silver, and may be alloyed.
Inventors
- 👤 G Bell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 21:11
CPC Classifications
H; H10; H10W; H10W99/00; B; B22; B22C; B22C9/00; B22C9/06; B22D; B22D19/00; B22D19/06
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
21 words
A process in accordance with claim 1 wherein the vacuum pressure during the process does not exceed thirty microns of mercury.
Claim 2
Dependent Claim
31 words
A process in accordance with claim 2 wherein the steps of melting the brazing alloy wafer and the casting slug are performed in a reduced atmosphere approximating one micron of mercury.
Claim 3
Dependent Claim
36 words
A process in accordance with claim 1 further including the step of first heating the evacuated mold to a temperature below the melting point of the brazing alloy and the casting slug to outgas the mold.
Claim 4
Dependent Claim
84 words
A process in accordance with claim 1 wherein the charging of the mold cavity includes the steps of placing an upwardly concave transitional element alloy brazing wafer in the mold cavity, centering a diamond macle in the brazing alloy wafer, capping the diamond macle with a downwardly concave brazing alloy wafer of a transitional element alloy, superimposing a casting slug upon the diamond and brazing alloy wafers, imposing a rod upon the casting slug and resting a weight upon the rod within the mold.
Claim 5
Dependent Claim
61 words
A process in accordance with claim 1 wherein the process of charging the mold cavity includes the steps of forming a recess in the bottom of the mold cavity, placing a diamond crystal within the recess, placing a brazing alloy wafer on the diamond, placing a casting slug upon the brazing alloy wafer, and placing a weight upon the casting slug.
Claim 6
Dependent Claim
23 words
A process in accordance with claim 1 including the step of separating the casting slug from the imposing weight with an inert wafer.
Claim 7
Dependent Claim
72 words
A process in accordance with claim 1 wherein after evacuating the mold the temperature of the mold and charge is raised to the melting point of the brazing alloy wafer and then the temperature is raised to the melting point of the casting slug, each of the temperatures being maintained for a cumulative time period less than the maximum tolerance of the diamond crystal to the heat range of the melting points.
Claim 8
Dependent Claim
65 words
A process in accordance with claim 1 wherein the brazing alloy wafer is an alloy of a heat-conducting element taken from a first group consisting of gold, silver and copper, alloyed with a smaller proportion of at least one element taken from a second group consisting of the transition metal elements, elements in the lanthanide series, elements in the actinide series, aluminum, silicon and boron.
Claim 9
Dependent Claim
36 words
A process in accordance with claim 9 wherein the proportion of the metal from the second group is between 0.1 to 30 percent by weight of the resulting alloy with the metal of the first group.
Claim 10
Dependent Claim
106 words
A bonding process for forming diamond heat sinks and tools and including the steps of forming a single stacked charge in a mold cavity, evacuating the mold to a vacuum level of less than thirty microns of mercury, heating the mold and charge to approximately 700* C. to outgas the mold, raising the temperature of the mold and charge to melt one of the components of the charge, raising the temperature of the mold and charge to melt the second component of the charge, and lowering the temperature of the mold and charge at a rate commensurate with annealing the unified charge within the mold cavity.
Claim 11
Dependent Claim
23 words
A bonding process in accordance with claim 11 further including the step of imposing a weight upon the charge in the mold cavity.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-04-16 | 1976-10-16 | 1977-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-16 | 1980-10-16 | 1981-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-16 | 1984-10-16 | 1985-04-17 | $7700.00 | Window Closed / Lapsed |