US5764073A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of estimating the reliability of module circuits
Assignee: Panasonic Holdings Corp
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Filing: 1996-05-22
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Granted: 1998-06-09
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Expires: 2016-05-22
Abstract
Abstract A method for estimating the reliability of modular circuits by conducting an accelerated life test of components comprising a modular circuit, applying the acceleration factor, etc. on test data thus obtained, and calculating a time to reach a predetermined rate of deterioration as the life time. By adding actual working conditions to the rate of deterioration, a minimum value for determining the deterioration of characteristics is obtained. A component having a value not higher than the minimum value or a rate not lower than the characteristic rate of degradation is then mounted on a printed circuit board comprising the modular circuit, to confirm whether the modular circuit functions normally.
Inventors
- 👤 Hideaki Sadamatsu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 17:25
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/28; G01R31/2851; G01R31/2855; G01R31/286; G01R31/2868; G01R31/287
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
176 words
A method for estimating the reliability of a modular circuit which comprises a printed circuit board having a printed circuit and electronic components mounted thereon and connected to said printed circuit, comprising the steps of: finding a degradation characteristic of a component mounted on said modular circuit by an accelerated life test, and determining an elapsed time for reaching a predetermined rate of deterioration as a life time; determining at least one of: a) a minimum value of said component and b) a characteristic rate of degradation of said component for determining a characteristic deterioration of said component corresponding said to said life time; replacing said component with another component having one of: a) a further minimum value not higher than said than said minimum value of said component, and b) a further characteristic rate of degradation not lower than said characteristic rate of degradation of said component on said modular circuit, and confirming, while simultaneously maintaining all other components of said printed circuit connected to said printed circuit, whether said modular circuit functions as intended.
Claim 2
Independent Claim
176 words
A method for estimating the reliability of a modular circuit which comprises a printed circuit board having a printed circuit and electronic components mounted thereon and connected to said printed circuit, comprising the steps of: finding a degradation characteristic of a component mounted on said modular circuit by an accelerated life test, and determining an elapsed time for reaching a predetermined rate of deterioration as a life time; determining at least one of: a) a minimum value of said component and b) a characteristic rate of degradation of said component for determining a characteristic deterioration of said component corresponding said to said life time; replacing said component with another component having one of: a) a further minimum value not higher than said than said minimum value of said component, and b) a further characteristic rate of degradation not lower than said characteristic rate of degradation of said component on said modular circuit, and confirming, while simultaneously maintaining all other components of said printed circuit connected to said printed circuit, whether said modular circuit functions as intended.
Claim 3
Dependent Claim
48 words
The estimation method of claim 1, wherein said determining step for determining at least one of said minimum value of said component and said characteristic rate of degradation of said component is based upon a spread in at least one of a plurality of characteristics of said component.
Claim 4
Dependent Claim
50 words
The estimation method of claim 2, wherein said determining step for determining at least one of said minimum value of said component and characteristic rate of degradation of said component is further based upon at least one of a plurality of environmental characteristics including a temperature characteristic of said component.
Claim 5
Dependent Claim
25 words
The estimation method of claim 3, wherein said temperature characteristic is within a range of actual temperatures in which said modular circuit functions as intended.
Claim 6
Independent Claim
152 words
A method of estimating the reliability of a modular circuit which comprises a printed circuit board having a printed circuit and electronic components mounted thereon and connected to said printed circuit, comprising the steps of: finding at least one degradation characteristic of a component mounted on said modular circuit by an accelerated life test, and determining at least one of a) a minimum value of said component and b) a characteristic rate of degradation of said component corresponding to a predetermined life time of said component; replacing said component with another component having one of; a) a further minimum value not higher than said minimum value of said component, and b) a characteristic not lower than said characteristic rate of degradation of said component on said modular circuit, and confirming, while simultaneously maintaining all other components of said printed circuit connected to said printed circuit, whether said modular circuit functions as intended.
Claim 7
Independent Claim
152 words
A method of estimating the reliability of a modular circuit which comprises a printed circuit board having a printed circuit and electronic components mounted thereon and connected to said printed circuit, comprising the steps of: finding at least one degradation characteristic of a component mounted on said modular circuit by an accelerated life test, and determining at least one of a) a minimum value of said component and b) a characteristic rate of degradation of said component corresponding to a predetermined life time of said component; replacing said component with another component having one of; a) a further minimum value not higher than said minimum value of said component, and b) a characteristic not lower than said characteristic rate of degradation of said component on said modular circuit, and confirming, while simultaneously maintaining all other components of said printed circuit connected to said printed circuit, whether said modular circuit functions as intended.
Claim 8
Dependent Claim
44 words
The estimation method of claim 5, wherein said finding step for determining said minimum value of said component and said characteristic rate of degradation of said component is based upon a spread in at least one of a plurality of characteristics of said component.
Claim 9
Dependent Claim
42 words
The estimation method of claim 6, wherein said finding step for determining said minimum value of said component and characteristic rate of degradation of said component is further based upon a plurality of environmental characteristics including a temperature characteristic of said component.
Claim 10
Dependent Claim
25 words
The estimation method of claim 7, wherein said temperature characteristic is within a range of actual temperatures in which said modular circuit functions as intended.
Claim 11
Independent Claim
177 words
A method of estimating the reliability of a modular circuit which comprises a printed circuit board having a printed circuit and electronic components mounted thereon and connected to said printed circuit, comprising the steps of: selecting a component suitable for an accelerated life test from a plurality of components which will be mounted on said modular circuit; finding a degradation characteristic of said component selected by an accelerated life test, and determining an elapsed time for reaching a predetermined rate of deterioration as a life time; determining at least one of: a) a minimum value of said component and b) a characteristic rate of degradation of said component based on said life time; replacing said component with another component having one of: a) a value not higher than said minimum value of said components and b) a characteristic not lower than said characteristic rate of degradation of said component on said modular circuit, and confirming, while simultaneously maintaining all other components of said printed circuit connected to said printed circuit, whether said modular circuit functions as intended.
Claim 12
Independent Claim
177 words
A method of estimating the reliability of a modular circuit which comprises a printed circuit board having a printed circuit and electronic components mounted thereon and connected to said printed circuit, comprising the steps of: selecting a component suitable for an accelerated life test from a plurality of components which will be mounted on said modular circuit; finding a degradation characteristic of said component selected by an accelerated life test, and determining an elapsed time for reaching a predetermined rate of deterioration as a life time; determining at least one of: a) a minimum value of said component and b) a characteristic rate of degradation of said component based on said life time; replacing said component with another component having one of: a) a value not higher than said minimum value of said components and b) a characteristic not lower than said characteristic rate of degradation of said component on said modular circuit, and confirming, while simultaneously maintaining all other components of said printed circuit connected to said printed circuit, whether said modular circuit functions as intended.
Claim 13
Dependent Claim
21 words
The estimation method of claim 9, wherein said selected component is a component which dominates the life of said modular circuit.
Claim 14
Dependent Claim
14 words
The estimation method of claim 10, wherein said selected component is an electrolytic capacitor.
Claim 15
Dependent Claim
18 words
The estimation method of claim 9, wherein each of said steps is based upon a plurality of components.
Claim 16
Independent Claim
218 words
A method of estimating the reliability of a modular circuit which comprises a printed circuit board having a printed circuit and electronic components mounted thereon and connected to said printed circuit, comprising the steps of: selecting a component from a plurality of components to be mounted on a modular circuit suitable for an accelerated life test; measuring a plurality of initial characteristic values of said selected component; conducting the accelerated life test on said selected component; measuring a plurality of values of said characteristics after the accelerated life test corresponding to said plurality of initial characteristic values; finding at least one of a degradation value and a rate of degradation based on said plurality of initial characteristic values and the plurality of values of said characteristics after said accelerated life test; determining a life time by comparing said rate of degradation and a predetermined rate of deterioration; determining a minimum value of said component for determining a deterioration of said plurality of characteristics of said component corresponding to said life time; replacing said component with another component having a further value not higher than said minimum value of said component on said modular circuit, and confirming, while simultaneously maintaining all other components of said printed circuit connected to said printed circuit, whether said modular circuit functions as intended.
Claim 17
Independent Claim
218 words
A method of estimating the reliability of a modular circuit which comprises a printed circuit board having a printed circuit and electronic components mounted thereon and connected to said printed circuit, comprising the steps of: selecting a component from a plurality of components to be mounted on a modular circuit suitable for an accelerated life test; measuring a plurality of initial characteristic values of said selected component; conducting the accelerated life test on said selected component; measuring a plurality of values of said characteristics after the accelerated life test corresponding to said plurality of initial characteristic values; finding at least one of a degradation value and a rate of degradation based on said plurality of initial characteristic values and the plurality of values of said characteristics after said accelerated life test; determining a life time by comparing said rate of degradation and a predetermined rate of deterioration; determining a minimum value of said component for determining a deterioration of said plurality of characteristics of said component corresponding to said life time; replacing said component with another component having a further value not higher than said minimum value of said component on said modular circuit, and confirming, while simultaneously maintaining all other components of said printed circuit connected to said printed circuit, whether said modular circuit functions as intended.
Claim 18
Dependent Claim
34 words
The estimation method of claim 13, wherein said step of determining said minimum value of said component is based upon a spread in at least one of a plurality of characteristics of said component.
Claim 19
Dependent Claim
36 words
The estimation method of claim 13, wherein said step of determining said minimum value of said component is based upon at least one of a plurality of environmental characteristics including a temperature characteristic of said component.
Claim 20
Dependent Claim
28 words
The estimation method of claim 13, wherein said accelerated life test applies a rated voltage to said component for a predetermined time at a predetermined temperature and humidity.
Claim 21
Dependent Claim
28 words
The estimation method of claim 9, wherein said accelerated life test applies a rated voltage to said component for a predetermined time at a predetermined temperature and humidity.
Claim 22
Dependent Claim
28 words
The estimation method of claim 5, wherein said accelerated life test applies a rated voltage to said component for a predetermined time at a predetermined temperature and humidity.
Claim 23
Dependent Claim
28 words
The estimation method of claim 1, wherein said accelerated life test applies a rated voltage to said component for a predetermined time at a predetermined temperature and humidity.
Claim 24
Dependent Claim
21 words
The estimation method of claim 9, wherein ones of the plurality of components are of a different type from one another.
Claim 25
Dependent Claim
36 words
The estimation method of claim 20, wherein the plurality of components of the different type include at least one of the group consisting of: a capacitor, a resistor, an integrated circuit, a transistor, and an inductor.
Claim 26
Dependent Claim
21 words
The estimation method of claim 13, wherein ones of the plurality of components are of a different type from one another.
Claim 27
Dependent Claim
36 words
The estimation method of claim 22, wherein the plurality of components of the different type include at least one of the group consisting of: a capacitor, a resistor, an integrated circuit, a transistor, and an inductor.
References Cited (Backward Citations)
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