Patent US5111137A successfully refreshed from Google Patents.
US5111137A
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US
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Method and apparatus for the detection of leakage current
Assignee: Agilent Technologies Inc
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Filing: 1990-10-29
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Granted: 1992-05-05
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Expires: 2010-10-29
Abstract
Abstract A method and apparatus for analyzing a semiconductor device having a diode formed therein. In its broadest sense, the invention involves irradiating the semiconductor device with electromagnetic radiation while monitoring the leakage current output from the diode contained in the semiconductor device. If the semiconductor device is present and properly soldered to the printed circuit board, an increase in the leakage current will be observed during the irradiation process. The increase in leakage current is also representative of the presence of intact bond wires at both the pin under test and the ground pin. The invention in a preferred form is shown to include a voltage source, electrically connected to the diode, for biasing the diode in a reverse direction, a current monitor, connected to monitor the leakage current from the diode and an electromagnetic radiation generator, positioned to provide electromagnetic radiation incident on the semiconductor device. It is preferred that the electromagnetic radiation be an ionizing radiation such as X-rays. However, such electromagnetic radiation can also be visible light, such as fluorescent light or incandescent light. In an especially preferred embodiment, the semiconductor device is first exposed to electromagnetic radiation, and thereafter the diode is biased in a reverse direction.
Inventors
- 👤 John M. Heumann
- 👤 Vance R. Harwood
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 17:17
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/26; G01R31/265; G01R31/28; G01R31/302; G01R31/308; G01R31/50; G01R31/52; G01R31/54
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
108 words
Apparatus for determining the quality of the mounting of a semiconductor device on a circuit board, the circuit board comprising first and second conductive paths and the semiconductor device comprising first and second leads and a diode effectively formed between said leads, wherein said first lead is associated with said first path and said second lead is associated with said second path , said apparatus comprising: a current monitor, connected to monitor the leakage current from said diode; and an electromagnetic radiation generator, positioned to provide electromagnetic radiation incident on said semiconductor device, wherein leakage current monitored during the provision of electromagnetic radiation is indicative of mounting quality.
Claim 2
Dependent Claim
108 words
Apparatus for determining the quality of the mounting of a semiconductor device on a circuit board, the circuit board comprising first and second conductive paths and the semiconductor device comprising first and second leads and a diode effectively formed between said leads, wherein said first lead is associated with said first path and said second lead is associated with said second path , said apparatus comprising: a current monitor, connected to monitor the leakage current from said diode; and an electromagnetic radiation generator, positioned to provide electromagnetic radiation incident on said semiconductor device, wherein leakage current monitored during the provision of electromagnetic radiation is indicative of mounting quality.
Claim 3
Dependent Claim
127 words
Apparatus for determining the quality of the mounting of a semiconductor device on a circuit board, the circuit board comprising first and second conductive paths and the semiconductor device comprising first and second leads and a diode effectively formed between said leads, wherein said first lead is associated with said first path and said second lead is associated with said second path said apparatus comprising: a voltage source, electrically connected to said first and second conductive paths, for biasing said diode in a reverse direction; a current monitor, connected to monitor the leakage current from said diode; and an electromagnetic radiation generator, positioned to provide electromagnetic radiation incident on said semiconductor device, wherein leakage current monitored during the provision of electromagnetic radiation is indicative of mounting quality.
Claim 4
Dependent Claim
127 words
Apparatus for determining the quality of the mounting of a semiconductor device on a circuit board, the circuit board comprising first and second conductive paths and the semiconductor device comprising first and second leads and a diode effectively formed between said leads, wherein said first lead is associated with said first path and said second lead is associated with said second path said apparatus comprising: a voltage source, electrically connected to said first and second conductive paths, for biasing said diode in a reverse direction; a current monitor, connected to monitor the leakage current from said diode; and an electromagnetic radiation generator, positioned to provide electromagnetic radiation incident on said semiconductor device, wherein leakage current monitored during the provision of electromagnetic radiation is indicative of mounting quality.
Claim 5
Dependent Claim
12 words
The apparatus of claim 2, wherein said electromagnetic radiation comprises ionizing radiation.
Claim 6
Dependent Claim
11 words
The apparatus of claim 3, wherein said ionizing radiation comprises X-rays.
Claim 7
Dependent Claim
26 words
The apparatus of claim 4, wherein said electromagnetic radiation generator provides said x-rays at an intensity in the range from 10 to 20 kilo electron volts.
Claim 8
Dependent Claim
12 words
The apparatus of claim 2, wherein said electromagnetic radiation comprises visible light.
Claim 9
Dependent Claim
13 words
The apparatus of claim 6, wherein said visible light comprises a fluorescent source.
Claim 10
Dependent Claim
13 words
The apparatus of claim 6, wherein said visible light comprises an incandescent source.
Claim 11
Dependent Claim
19 words
The apparatus of claim 2, wherein said source is electrically connected to said diode by twisted shielded pair wiring.
Claim 12
Dependent Claim
17 words
The apparatus of claim 2, wherein said voltage source provides a voltage approximately equal to 2 volts.
Claim 13
Dependent Claim
28 words
The apparatus of claim 2, wherein said semiconductor device is first exposed to said electromagnetic radiation, and thereafter said voltage source biases said diode in a reverse direction.
Claim 14
Dependent Claim
25 words
The apparatus of claim 2, wherein said electromagnetic generator collimates said electromagnetic radiation so that said electromagnetic radiation is incident on only said semiconductor device.
Claim 15
Independent Claim
119 words
A method for determining the quality of the mounting of a semiconductor device on a circuit board, the circuit board comprising first and second conductive paths and the semiconductor device comprising first and second leads and a diode effectively formed between said leads, wherein said first lead is associated with said first path and said second lead is associated with said second path, said method comprising the steps of: biasing said diode in a reverse direction, by connecting a voltage source to said first and second conductive paths; monitoring the leakage current from said diode; and providing electromagnetic radiation incident on said semiconductor device, wherein leakage current monitored during the provision of electromagnetic radiation is indicative of mounting quality.
Claim 16
Independent Claim
119 words
A method for determining the quality of the mounting of a semiconductor device on a circuit board, the circuit board comprising first and second conductive paths and the semiconductor device comprising first and second leads and a diode effectively formed between said leads, wherein said first lead is associated with said first path and said second lead is associated with said second path, said method comprising the steps of: biasing said diode in a reverse direction, by connecting a voltage source to said first and second conductive paths; monitoring the leakage current from said diode; and providing electromagnetic radiation incident on said semiconductor device, wherein leakage current monitored during the provision of electromagnetic radiation is indicative of mounting quality.
Claim 17
Dependent Claim
19 words
The method of claim 13, wherein the step of providing electromagnetic radiation comprises the step of providing ionizing radiation.
Claim 18
Dependent Claim
18 words
The method of claim 14, wherein the step of providing ionizing radiation comprises the step of providing X-rays.
Claim 19
Dependent Claim
30 words
The method of claim 15, wherein the step of providing X-rays comprises the step of providing X-rays at an intensity in the range from 10 to 20 kilo electron volts.
Claim 20
Dependent Claim
19 words
The method of claim 13, wherein the step of providing electromagnetic radiation comprises the step of providing visible light.
Claim 21
Dependent Claim
20 words
The method of claim 17, wherein the step of providing visible light comprises the step of providing a fluorescent source.
Claim 22
Dependent Claim
20 words
The method of claim 17, wherein the step of providing visible light comprises the step of providing an incandescent source.
Claim 23
Dependent Claim
28 words
The method of claim 13, wherein the step of biasing said diode comprises the step of connecting a voltage source to said diode by twisted shielded pair wiring
Claim 24
Dependent Claim
28 words
The method of claim 13, wherein the step of biasing said diode in a reverse direction comprises the step of providing a voltage approximately equal to 2 volts.
Claim 25
Dependent Claim
31 words
The method of claim 13, wherein the step of providing electromagnetic radiation incident on said semiconductor device is initiated prior to the step of biasing said diode in a reverse direction.
Claim 26
Dependent Claim
68 words
The method of claim 13, wherein said semiconductive device comprises an opaque casing and wherein said electromagnetic radiation comprises a wavelength and an energy level, wherein said step of providing electromagnetic energy comprises providing said energy at a wavelength and at an energy level such that said electromagnetic radiation penetrates said casing and deposits sufficient energy in the semiconductive device to cause a measurable increase in leakage current.
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