# US 7,607,824 B2 · Method of analyzing electrical connection and test system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,607,824 B2 - Document ID: US7607824B2 - Status: Granted - Kind: B2 - Application number: 11/586,456 - Filed: 2006-10-25 - Published: 2008-05-01 - Granted: 2009-10-27 - Earliest claimed: 2006-10-25 - Assignees: Delphi Technologies, Inc. - Inventors: Brian Lee Chandler; Frederick F. Kuhlman - Web page: https://patentgrep.com/patent/US7607824B2 ## CPC - G01R 31/70: Testing of connections between components and printed circuit boards (G01R31/68 takes precedence) - G01N 25/72: Investigating presence of flaws - H05K 3/308: {Adaptations of leads (connectors to printed circuits H01R12/00)} - H05K 1/0269: {for visual or optical inspection} - H05K 2201/1059: Connections made by press-fit insertion - H05K 2203/163: Monitoring a manufacturing process - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS ## Abstract A test system and method of analyzing a pin to circuit connection on a substrate is provided. The method includes applying thermal energy to the pin or the substrate at a location outside of the pin to circuit interface, and measuring infrared radiation near the pin to circuit interface. The method also includes the step of analyzing the measured infrared radiation to determine thermal energy distribution near the pin to circuit interface resulting from thermal conductivity at the interface. The method further includes the step of determining sufficiency of the pin to circuit electrical and mechanical connection based on the determined thermal energy distribution. ## Claims ### Claim 1 A method of determining quality of an electrical connection of a pin connected to a circuit at an interface on a substrate of an electrical assembly, said method comprising the steps of: applying thermal energy to at least one of the pin and the substrate at a location outside of the pin to circuit interface; measuring thermal energy radiation near the pin to circuit interface; analyzing the measured thermal energy radiation to determine thermal energy distribution near the pin to circuit interface resulting from thermal conductivity at the interface; and determining quality of the pin to circuit electrical connection based on the determined thermal energy distribution; wherein the pin comprises a compliant pin press-fit into a plated through hole in the substrate. ### Claim 2 (depends on 1) The method as defined in claim 1, wherein the step of measuring thermal energy radiation comprises measuring infrared radiation. ### Claim 3 (depends on 1) The method as defined in claim 1, wherein the step of applying thermal energy comprising applying infrared energy. ### Claim 4 (depends on 1) The method as defined in claim 1, wherein the step of analyzing the measured thermal energy radiation comprises comparing the thermal energy distribution to known distributions for acceptable and unacceptable electrical assemblies. ### Claim 5 (depends on 1) The method as defined in claim 1, wherein the step of applying thermal energy comprises applying thermal energy to the pin. ### Claim 6 (depends on 1) The method as defined in claim 1, wherein the step of applying thermal energy comprises applying thermal energy to the substrate. ### Claim 7 (depends on 1) The method as defined in claim 1, wherein the step of applying thermal energy comprises applying electrical current to the pin. ### Claim 8 (depends on 1) The method as defined in claim 1, wherein the step of measuring thermal energy radiation near the pin to circuit interface comprises measuring thermal energy radiation within two millimeters of the interface. ### Claim 9 (depends on 1) The method as defined in claim 1, wherein the step of analyzing the measured thermal energy radiation to determine thermal energy distribution comprises analyzing rate of change of thermal energy near the pin to circuit interface. ### Claim 10 A method of determining quality of an electrical connection of a compliant press-fit pin inserted into a conductive receptacle at an interface on a substrate of an electrical assembly, said method comprising the steps of: applying thermal energy to at least one of the compliant press-fit pin and the substrate at a location outside of the pin to receptacle interface; measuring thermal energy radiation near the pin to receptacle interface; analyzing the measured thermal energy radiation to determine thermal energy distribution near the pin to receptacle interface resulting from thermal conductivity at the interface; and determining quality of the pin to receptacle electrical connection based on the determined thermal energy distribution. ### Claim 11 (depends on 10) The method as defined in claim 10, wherein the step of measuring thermal energy radiation comprises measuring infrared radiation. ### Claim 12 (depends on 10) The method as defined in claim 10, wherein the step of applying thermal energy comprising applying infrared energy. ### Claim 13 (depends on 10) The method as defined in claim 10, wherein the receptacle comprises a plated through hole in the substrate. ### Claim 14 (depends on 10) The method as defined in claim 10, wherein the step of analyzing the measured thermal energy radiation comprises comparing the thermal energy distribution to known distributions for acceptable and unacceptable electrical assemblies. ### Claim 15 (depends on 10) The method as defined in claim 10, wherein the step of applying thermal energy comprises applying thermal energy to the pin. ### Claim 16 (depends on 10) The method as defined in claim 10, wherein the step of applying thermal energy comprises applying thermal energy to the substrate. ### Claim 17 (depends on 10) The method as defined in claim 10, wherein the step of applying thermal energy comprises applying electrical current to the pin. ### Claim 18 (depends on 10) The method as defined in claim 10, wherein the step of measuring thermal energy radiation near the pin to circuit interface comprises measuring thermal energy radiation within two millimeters of the interface. ### Claim 19 (depends on 10) The method as defined in claim 10, wherein the step of analyzing the measured thermal energy radiation to determine thermal energy distribution comprises analyzing rate of change of thermal energy near the pin to circuit interface. ### Claim 20 A test system for determining quality of an electrical connection between a pin and a circuit at an interface on a substrate, said test system comprising: a heat source for applying thermal energy to one of a pin and a substrate at a location outside of the pin to circuit interface; a thermal energy measuring device for measuring thermal energy radiation near the pin to circuit interface; and a processor for analyzing the measured thermal energy radiation to determine thermal energy distribution near the pin to circuit interface resulting from thermal conductivity at the interface, said processor further determining quality of the pin to circuit electrical connection based on the determined thermal energy distribution; wherein the test system determines quality of a compliant press-fit pin inserted into a plated through hole on the substrate. ### Claim 21 (depends on 20) The test system as defined in claim 20, wherein the thermal energy measuring device comprises an infrared camera. ### Claim 22 (depends on 20) The test system as defined in claim 20, wherein the thermal energy source applies thermal energy radiation to the pin. ### Claim 23 (depends on 20) The test system as defined in claim 20, wherein the thermal energy source applies thermal energy radiation to the substrate. ### Claim 24 (depends on 20) The test system as defined in claim 20, wherein the thermal energy measuring device measures thermal radiation within about two millimeters of the interface. ### Claim 25 (depends on 20) The test system as defined in claim 20, wherein the processor analyzes rate of change of thermal energy to determine the thermal energy distribution.