# US 8,785,217 B2 · Tunable radiation source > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,785,217 B2 - Document ID: US8785217B2 - Status: Granted - Kind: B2 - Application number: 13/230,798 - Filed: 2011-09-12 - Published: 2013-03-14 - Granted: 2014-07-22 - Earliest claimed: 2011-09-12 - Assignees: International Business Machines Corporation - Applicants: Michael A. Gaynes; Michael S. Gordon; Nancy C. LaBianca; Kenneth P. Rodbell - Inventors: Michael A. Gaynes; Michael S. Gordon; Nancy C. LaBianca; Kenneth P. Rodbell - Web page: https://patentgrep.com/patent/US8785217B2 ## CPC - H10W 42/25: against alpha rays, e.g. for outer space applications - G01R 31/2881: {related to environmental aspects other than temperature, e.g. humidity or vibrations} - G06F 30/367: Design verification, e.g. using simulation, simulation program with integrated circuit emphasis [SPICE], direct methods or relaxation methods - H10W 74/15: on active surfaces of flip-chip devices, e.g. underfills - H10W 90/724: {between a chip and a stacked insulating package substrate, interposer or RDL} - H10W 90/734: {between a chip and a stacked insulating package substrate, interposer or RDL} - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract An energy distribution of soft error-inducing radiation likely to be encountered by an electronic circuit during operation is determined. A tuned radiation source having a source energy distribution similar to the determined energy distribution is prepared. The electronic circuit is tested using the tuned radiation source. ## Claims ### Claim 1 A method comprising: determining an energy distribution of soft error-inducing radiation likely to be encountered by an electronic circuit during operation; preparing a tuned radiation source having a source energy distribution similar to said energy distribution determined in said determining step; and testing said electronic circuit with said tuned radiation source; wherein said preparing step comprises interspersing a plurality of radiation sources with a plurality of absorbers. ### Claim 2 (depends on 1) The method of claim 1, wherein said preparing comprises spin coating. ### Claim 3 (depends on 1) The method of claim 1, wherein said preparing comprises rastering a dispensing needle under robotic control. ### Claim 4 (depends on 1) The method of claim 1, wherein said preparing comprises at least one of stencil and screen printing. ### Claim 5 (depends on 1) The method of claim 1, wherein said preparing comprises: selecting an alpha-particle emitting isotope with an emission energy that is greater than a maximum predicted in said determining step; selecting a desired activity of said alpha-particle emitting isotope; selecting said absorber; modeling alpha particle transmission through said absorber; checking whether a result of said modeling step closely matches said energy distribution from said determining step; and fabricating said tuned radiation source in accordance with said modeling if said checking is affirmative. ### Claim 6 (depends on 5) The method of claim 5, further comprising, if said checking is not affirmative, iterating until said checking is affirmative. ### Claim 7 A method comprising: determining an energy distribution of soft error-inducing radiation likely to be encountered by an electronic circuit during operation; preparing a tuned radiation source having a source energy distribution similar to said energy distribution determined in said determining step; and testing said electronic circuit with said tuned radiation source; wherein said preparing step comprises depositing on a substrate a first underfill layer doped with a first radioactive material and a second underfill layer doped with a second radioactive material different than said first radioactive material. ### Claim 8 A method comprising: determining an energy distribution of soft error-inducing radiation likely to be encountered by an electronic circuit during operation; preparing a tuned radiation source having a source energy distribution similar to said energy distribution determined in said determining step; and testing said electronic circuit with said tuned radiation source; wherein said preparing step comprises depositing on a substrate an underfill layer doped with a first radioactive material and a second radioactive material different than said first radioactive material. ### Claim 9 A method comprising: determining an energy distribution of soft error-inducing radiation likely to be encountered by an electronic circuit during operation; preparing a tuned radiation source having a source energy distribution similar to said energy distribution determined in said determining step; and testing said electronic circuit with said tuned radiation source; wherein said preparing step comprises applying said tuned radiation source to said electronic circuit as an underfill. ### Claim 10 A method comprising: determining an energy distribution of soft error-inducing radiation likely to be encountered by an electronic circuit during operation; preparing a tuned radiation source having a source energy distribution similar to said energy distribution determined in said determining step; and testing said electronic circuit with said tuned radiation source; wherein said preparing step comprises preparing said tuned radiation source as an external source; wherein said testing step comprises bringing said external source into proximity with said electronic circuit; wherein said electronic circuit comprises a chip that is not mounted in a package; wherein said bringing said external source into proximity comprises laying said tuned radiation source on top of said chip; and wherein said testing comprises probing said chip with a probe. ### Claim 11 A method comprising: determining a pillbox shaped energy distribution appropriate for calibrating a gas proportional detector; preparing a tuned radiation source having a source energy distribution similar to said energy distribution determined in said determining step; and calibrating said gas proportional detector with said tuned radiation source. ### Claim 12 (depends on 11) The method of claim 11, wherein said preparing step comprises interspersing a plurality of radiation sources with a plurality of absorbers. ### Claim 13 A method comprising: modeling an energy distribution of soft error-inducing radiation likely to be encountered by an electronic circuit during operation; selecting an alpha-particle emitting isotope with an emission energy that is greater than a maximum predicted in said modeling step; selecting a desired activity of said alpha-particle emitting isotope; selecting an absorber; modeling alpha particle transmission through said absorber; checking whether a result of said step of modeling said alpha particle transmission through said absorber closely matches said energy distribution from said step of modeling said energy distribution of said soft error-inducing radiation likely to be encountered by said electronic circuit during operation; and specifying a tuned radiation source in accordance with said modeling steps if said checking is affirmative. ### Claim 14 (depends on 13) The method of claim 13, further comprising fabricating said tuned radiation source in accordance with said specifying. ### Claim 15 (depends on 13) The method of claim 13, further comprising, if said checking is not affirmative, iterating until said checking is affirmative. ### Claim 16 (depends on 13) The method of claim 13, further comprising providing a system, wherein the system comprises at least one software module, embodied in a non-transitory manner on a non-transitory computer-readable storage medium, and wherein the at least one distinct software module comprises a modeling engine module which implements a quantum mechanical treatment of ion-atom collisions; wherein: said modeling steps are carried out by said modeling engine module executing on at least one hardware processor.