US4272986A
Expired / Lapsed
US
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Method and means for measuring moisture content of hermetic semiconductor devices
Assignee: Harris Corp
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Filing: 1979-04-16
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Granted: 1981-06-16
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Expires: 1999-04-16
Abstract
Abstract The moisture content of a hermetically sealed semiconductor device is a function of the dew point of the cavity atmosphere which is the temperature of maximum surface conductivity. A pattern of interdigitated thin film aluminum conductors is provided on an impurity free, non-porous silicon oxide insulative substrate. The surface conductivity of this structure rises as moisture condenses onto and between the conductors as the temperature is reduced at a slow controlled rate to the dew point temperature. The amplitude of the maximum surface conductivity is proportional to ionic impurity concentration.
Inventors
- 👤 Robert K. Lowry
- 👤 Larry A. Miller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:34
CPC Classifications
G; G01; G01N; G01N25/00; G01N25/56; G01N25/66; G01N25/68
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
85 words
A method of measuring the amount of moisture in a hermetically sealed semiconductor device package comprising: providing parallel conductive elements having a thickness no greater than 12,000 angstroms and a separation of no greater than 0.5 mils on an insulative surface is said package; simultaneously lowering the temperature of said package at a rate no greater than 15° centigrade per minute to condense the water vapor and measuring the conductivity between said conductive elements; and determining the moisture content from the temperature of maximum conductivity.
Claim 2
Independent Claim
85 words
A method of measuring the amount of moisture in a hermetically sealed semiconductor device package comprising: providing parallel conductive elements having a thickness no greater than 12,000 angstroms and a separation of no greater than 0.5 mils on an insulative surface is said package; simultaneously lowering the temperature of said package at a rate no greater than 15° centigrade per minute to condense the water vapor and measuring the conductivity between said conductive elements; and determining the moisture content from the temperature of maximum conductivity.
Claim 3
Dependent Claim
28 words
The method of claim 2 wherein providing said conductive strips includes forming interdigitized aluminum conductive strips on a substantially impurity free, substantially non-porous, insulative surface in said package.
Claim 4
Dependent Claim
24 words
The method of claim 2 wherein said package is heated at a temperature in the range of 100° Centigrade prior to lowering the temperature.
Claim 5
Dependent Claim
27 words
The method of claim 1 wherein said package includes metallic portions and including the step of insulating said metallic portions to prevent condensation on the metallic surfaces.
Claim 6
Dependent Claim
19 words
The method of claim 1 wherein said temperature is lowered at a rate of 10 degrees centigrade per minute.
Claim 7
Dependent Claim
22 words
The method of claim 1 wherein said conductive strips are formed on a non-porous, thermal grown insulative surface of a semiconductor substrate.
Claim 8
Independent Claim
89 words
A method of measuring dew point of the atmosphere in a sealed cavity comprising: providing a surface conductivity sensor in a sealed cavity having parallel conductors of a thickness no greater than 12,000 angstroms and a separation of no greater than 0.5 mils on a non-porous insulative surface; and simultaneously lowering the temperature in said cavity at a rate no greater than 15° centigrade per minute to determine dew point as the temperature of maximum conductivity and measuring the conductivity of liquid condensed on said surface between said conductors.
Claim 9
Independent Claim
89 words
A method of measuring dew point of the atmosphere in a sealed cavity comprising: providing a surface conductivity sensor in a sealed cavity having parallel conductors of a thickness no greater than 12,000 angstroms and a separation of no greater than 0.5 mils on a non-porous insulative surface; and simultaneously lowering the temperature in said cavity at a rate no greater than 15° centigrade per minute to determine dew point as the temperature of maximum conductivity and measuring the conductivity of liquid condensed on said surface between said conductors.
Claim 10
Dependent Claim
37 words
The method of measuring dew point according to claim 7 wherein said sealed cavity is formed by a ceramic housing hermetically sealed and said surface is substantially impurity free silicon oxide surface and said conductors are aluminum.
Claim 11
Independent Claim
83 words
A method of measuring the concentration of dissolved ions in the atmosphere of a hermetically sealed semiconductor device package comprising: providing a surface conductivity sensor on a non-porous surface in said sealed cavity; heating said cavity at a temperature sufficient to vaporize the moisture in said cavity; simultaneously lowering the temperature in said cavity and measuring the surface conductivity of liquid condensed on said sensor; and determining the approximate concentration of dissolved ions from the magnitude of the point of maximum surface conductivity.
Claim 12
Independent Claim
83 words
A method of measuring the concentration of dissolved ions in the atmosphere of a hermetically sealed semiconductor device package comprising: providing a surface conductivity sensor on a non-porous surface in said sealed cavity; heating said cavity at a temperature sufficient to vaporize the moisture in said cavity; simultaneously lowering the temperature in said cavity and measuring the surface conductivity of liquid condensed on said sensor; and determining the approximate concentration of dissolved ions from the magnitude of the point of maximum surface conductivity.
Claim 13
Dependent Claim
38 words
The method of measuring concentration of dissolved ions according to claim 9 wherein said sensor includes a pair of interdigitized conductors having a thickness no greater than 12,000 angstroms and a separation of no greater than 0.5 mils.
Claim 14
Dependent Claim
37 words
The method of measuring concentration of dissolved ions according to claim 9 wherein said heating is to a temperature in the range of 100° centigrade and lowered at a rate no greater than 15° centigrade per minute.
Claim 15
Dependent Claim
123 words
A hermetically sealed package including a semiconductive device and an integral moisture detector comprising: means forming a cavity for retaining said semiconductive device; means hermetically sealing said cavity; a plurality of metallic leads extending from within said cavity to the outside of said package; a non-porous insulative oxide layer in said package; exposed parallel conductors having thickness no greater than 12,000 angstroms and a separation of no greater than 0.5 mils formed on said oxide layer; and electrodes connecting said conductors to a pair of said leads whereby the moisture content of the sealed package may be determined by monitoring the conductivity of liquid condensed on the surface between said conductors in the temperature region of the dew point of the cavity atmosphere.
Claim 16
Dependent Claim
123 words
A hermetically sealed package including a semiconductive device and an integral moisture detector comprising: means forming a cavity for retaining said semiconductive device; means hermetically sealing said cavity; a plurality of metallic leads extending from within said cavity to the outside of said package; a non-porous insulative oxide layer in said package; exposed parallel conductors having thickness no greater than 12,000 angstroms and a separation of no greater than 0.5 mils formed on said oxide layer; and electrodes connecting said conductors to a pair of said leads whereby the moisture content of the sealed package may be determined by monitoring the conductivity of liquid condensed on the surface between said conductors in the temperature region of the dew point of the cavity atmosphere.
Claim 17
Dependent Claim
26 words
The hermetically-sealed package according to claim 12 wherein said oxide layer is a substantially impurity free, substantially non-porous silicon oxide and said conductors are interdigitated aluminum.
Claim 18
Dependent Claim
17 words
The hermetically-sealed package according to claim 12 wherein said means forming said cavity is a ceramic material.
Claim 19
Dependent Claim
87 words
In a hermetically-sealed package including a semiconductor device in a sealed cavity of said device package, the improvement comprising means in said cavity for facilitating the measurement of dew point for the atmosphere in the sealed cavity, said means including parallel conductor means formed having a thickness no greater than 12,000 angstroms and a separation of no greater than 0.5 mils on a non-porous, thermally grown insulative surface in said sealed cavity for detecting the presence of condensed moisture on said insulative surface between said conductor means.
Claim 20
Dependent Claim
87 words
In a hermetically-sealed package including a semiconductor device in a sealed cavity of said device package, the improvement comprising means in said cavity for facilitating the measurement of dew point for the atmosphere in the sealed cavity, said means including parallel conductor means formed having a thickness no greater than 12,000 angstroms and a separation of no greater than 0.5 mils on a non-porous, thermally grown insulative surface in said sealed cavity for detecting the presence of condensed moisture on said insulative surface between said conductor means.
Claim 21
Dependent Claim
19 words
The hermetically-sealed package according to claim 15 wherein said insulative surface is an oxide layer of said semiconductor device.
Claim 22
Dependent Claim
25 words
The hermetically-sealed package according to claim 16 wherein said oxide layer is a substantially impurity free, substantially non-porous silicon oxide and said conductors are aluminum.
Claim 23
Dependent Claim
15 words
The hermetically-sealed package according to claim 15 wherein said package is of a ceramic material.
Claim 24
Dependent Claim
78 words
In a hermetically sealed package including a semiconductor device in a sealed cavity of said package, the improvement comprising means in said cavity for facilitating the measurement of concentration of dissolved ions in the atmosphere in the sealed cavity, said means including a pair of parallel conductor means formed on a non-porous insulative surface in said sealed cavity for detecting the dissolved ion concentration of the liquid condensed onto said insulative surface between said pair of conductor means.
Claim 25
Dependent Claim
78 words
In a hermetically sealed package including a semiconductor device in a sealed cavity of said package, the improvement comprising means in said cavity for facilitating the measurement of concentration of dissolved ions in the atmosphere in the sealed cavity, said means including a pair of parallel conductor means formed on a non-porous insulative surface in said sealed cavity for detecting the dissolved ion concentration of the liquid condensed onto said insulative surface between said pair of conductor means.
Claim 26
Dependent Claim
26 words
The hermetically sealed package according to claim 19 wherein said conductor means have a thickness not exceeding 12,000 angstrom and a separation not exceeding 0.5 mils.
Claim 27
Dependent Claim
47 words
A surface conductivity moisture sensor comprising a non-porous, impurity free insulative surface on a substrate and interdigitized metallic conductors having a thickness no greater than 12,000 angstroms and a separation of no greater than 0.5 mil for detecting condensed moisture on said insulative surface between said conductors.
Claim 28
Dependent Claim
47 words
A surface conductivity moisture sensor comprising a non-porous, impurity free insulative surface on a substrate and interdigitized metallic conductors having a thickness no greater than 12,000 angstroms and a separation of no greater than 0.5 mil for detecting condensed moisture on said insulative surface between said conductors.
Claim 29
Dependent Claim
18 words
The surface conductivity moisture sensor according to claim 21 wherein said insulative surface is thermal grown silicon oxide.
Claim 30
Dependent Claim
14 words
The surface conductivity moisture sensor according to claim 21 wherein said conductors are aluminum.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-06-15 | 1984-12-15 | 1985-06-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-06-15 | 1988-12-15 | 1989-06-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-06-15 | 1992-12-15 | 1993-06-16 | $7700.00 | Window Closed / Lapsed |