US4784974A
Expired / Lapsed
US
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Method of making a hermetically sealed semiconductor casing
Assignee: Olin Corp
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Filing: 1986-10-31
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Granted: 1988-11-15
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Expires: 2006-10-31
Abstract
Abstract An improved hermetically sealed semiconductor casing and a process for producing the casing are disclosed. This casing includes a lead frame having an electrical device affixed thereto. A base member is glass bonded to a matching surface of the lead frame. A metal window frame shaped device is provided having one surface with a refractory oxide coating and a second opposite readily solderable surface. The refractory oxide layer of the window frame device is glass bonded to the lead frame and the base member. The semiconductor or electrical device is connected to the lead frame after the window frame has been glass bonded into place. A metal lid having a solderable surface is solder bonded to the solderable surface of the window frame to hermetically seal the electrical device within the casing.
Inventors
- 👤 Sheldon H. Butt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 22:47
CPC Classifications
H; H10; H10W; H10W76/00; H10W76/60; H10W95/00; H10W70/00; H10W70/60; H10W70/67; H10W70/68; H10W70/682; H10W70/685; H10W72/00; H10W72/50; H10W72/551; H10W72/552; H10W72/5522; H10W72/5524; H10W72/851; H10W72/874; H10W72/884; H10W90/00; H10W90/701; H10W90/731; H10W90/734; H10W90/751; H10W90/756; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49121; Y10T29/49124; Y10T29/49126; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12535; Y10T428/12611
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
342 words
The process of hermetically sealing a semiconductor casing for an electrical component, comprising the steps of: providing a metal alloy leadframe having first and second opposite surfaces and being adapted to have said electrical component connected thereto; providing a metal or metal alloy base member; providing a metal or metal alloy window frame and shaped component comprising a bi-clad of first and second metal or metal alloy components, said first metal or metal alloy component having at least a first surface for improved glass or ceramic bonding, said second metal or metal alloy component having at least a first surface being readily solderable; selecting said leadframe, base member, and the first metal or metal alloy component of said window frame component from a metal or metal alloy having a coefficient of thermal expansion of from about 165×10 -7 to about 170×10 -7 in./in./°C.; providing a metal or metal alloy lid having at least a first surface being readily solderable; providing a glass or ceramic component having a coefficient of thermal expansion of at least about 160×10 -7 in./in./°C., said coefficient of thermal expansion of said glass or ceramic component being closely matched to the coefficients of thermal expansion of said metal or metal alloy leadframe, said metal or metal alloy base member, and the first metal or metal alloy component of said window frame shaped component; disposing said leadframe with said glass or ceramic component against the first and second opposite surfaces of said leadframe between the first surface of the first metal or metal alloy component of the window frame shaped component and the first surface of said metal or metal alloy base member; glass bonding said leadframe to said base member and said window frame component without generating substantial thermal stress from exposure to thermal cycling; mounting said electrical component to said leadframe; and soldering the first readily solderable surface of the second component of said window frame component to the first readily solderable surface of the metal or metal alloy lid whereby said semiconductor casing is substantially hermetically sealed.
Claim 2
Dependent Claim
342 words
The process of hermetically sealing a semiconductor casing for an electrical component, comprising the steps of: providing a metal alloy leadframe having first and second opposite surfaces and being adapted to have said electrical component connected thereto; providing a metal or metal alloy base member; providing a metal or metal alloy window frame and shaped component comprising a bi-clad of first and second metal or metal alloy components, said first metal or metal alloy component having at least a first surface for improved glass or ceramic bonding, said second metal or metal alloy component having at least a first surface being readily solderable; selecting said leadframe, base member, and the first metal or metal alloy component of said window frame component from a metal or metal alloy having a coefficient of thermal expansion of from about 165×10 -7 to about 170×10 -7 in./in./°C.; providing a metal or metal alloy lid having at least a first surface being readily solderable; providing a glass or ceramic component having a coefficient of thermal expansion of at least about 160×10 -7 in./in./°C., said coefficient of thermal expansion of said glass or ceramic component being closely matched to the coefficients of thermal expansion of said metal or metal alloy leadframe, said metal or metal alloy base member, and the first metal or metal alloy component of said window frame shaped component; disposing said leadframe with said glass or ceramic component against the first and second opposite surfaces of said leadframe between the first surface of the first metal or metal alloy component of the window frame shaped component and the first surface of said metal or metal alloy base member; glass bonding said leadframe to said base member and said window frame component without generating substantial thermal stress from exposure to thermal cycling; mounting said electrical component to said leadframe; and soldering the first readily solderable surface of the second component of said window frame component to the first readily solderable surface of the metal or metal alloy lid whereby said semiconductor casing is substantially hermetically sealed.
Claim 3
Dependent Claim
37 words
The process as set out in claim 1 including the step of selecting said first metal alloy from a first copper alloy having a coefficient of thermal expansion of about 165×10 -7 to about 170×10 -7 in./in./°C.
Claim 4
Dependent Claim
53 words
The process of claim 2 wherein: said first and second opposite surfaces of said leadframe have a first refractory oxide layer thereon; said at least one surface of said first member has a second refractory oxide layer thereon; and said first component has a first surface with a third refractory oxide layer thereon.
Claim 5
Dependent Claim
46 words
The process as in claim 3 wherein: said first copper alloy comprises an effective amount of up to about 12% aluminum to form a refractory oxide and the balance essentially copper; and said first, second and third refractory oxide layers include Al 2 O 3 .
Claim 6
Dependent Claim
33 words
The process as set out in claim 4 including the step of selecting said first alloy to consist essentially of 2.5 to 3.1% aluminum, 1.5 to 2.1% silicon, and the balance essentially copper.
Claim 7
Dependent Claim
31 words
The process as in claim 2 including the step of cladding said base member with a substantially high conductivity metal or alloy for providing improved thermal conductivity of said semiconductor casing.
Claim 8
Dependent Claim
26 words
The process as set forth in claim 6 including the step of forming said metal or metal alloy lid of a second copper or copper alloy.
References Cited (Backward Citations)
US3381080A
Cited
US3729820A
Cited
US3730779A
Cited
US3726987A
Cited
US3852148A
Cited
US3698964A
Cited
US4517584A
Cited
US4663649A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-11-15 | 1992-05-16 | 1992-11-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-11-15 | 1996-05-16 | 1996-11-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-11-15 | 2000-05-16 | 2000-11-15 | $7700.00 | Window Closed / Lapsed |