# US 10,286,471 B2 · Solder paste misprint cleaning > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,286,471 B2 - Document ID: US10286471B2 - Status: Granted - Kind: B2 - Application number: 15/924,484 - Filed: 2018-03-19 - Published: 2018-07-05 - Granted: 2019-05-14 - Earliest claimed: 2016-06-06 - Assignees: International Business Machines Corporation - Applicants: International Business Machines Corporation - Inventors: Xingquan Dong; Yanlong Hou; LiCen Mu; Ben Wu; WeiFeng Zhang - Web page: https://patentgrep.com/patent/US10286471B2 ## CPC - B23K 1/018: Unsoldering; Removal of melted solder or other residues - B23K 1/0016: {Soldering of electronic components} - B23K 3/04: Heating appliances - B23K 3/08: Auxiliary devices therefor - B23K 31/02: relating to soldering or welding - B23K 31/12: relating to investigating the properties, e.g. the weldability, of materials - B23K 35/02: characterised by mechanical features, e.g. shape - B23K 35/0222: {for use in soldering or brazing (B23K35/0205 takes precedence)} - B23K 35/0244: {Powders, particles or spheres; Preforms made therefrom} - B23K 35/025: {Pastes, creams or slurries} - B23K 35/262: {Sn as the principal constituent} - B23K 35/3006: {Ag as the principal constituent} - B23K 35/302: {Cu as the principal constituent} - B23K 35/3033: {Ni as the principal constituent} - B23K 35/3053: {Fe as the principal constituent} - B23K 35/36: Selection of non-metallic compositions, e.g. coatings or fluxes (B23K35/34 takes precedence); Selection of soldering or welding materials, conjoint with selection of non-metallic compositions, both selections being of interest - H05K 3/225: {Correcting or repairing of printed circuits (H05K1/0292, H05K3/222, H05K3/288, H05K3/4685 take precedence)} - H05K 3/3485: Application of solder paste, slurry or powder (using printing techniques to form the desired conductive pattern of the printed circuit by applying conductive material H05K3/12) - B23K 2101/42: Printed circuits - G05B 2219/37215: Inspect application of solder paste, glue to workpiece - G05B 2219/45235: Dispensing adhesive, solder paste, for pcb - H05K 3/34: by soldering - H05K 2201/083: Magnetic materials - H05K 2203/0445: Removing excess solder on pads; removing solder bridges, e.g. for repairing or reworking - H05K 2203/104: Using magnetic force, e.g. to align particles or for a temporary connection during processing - H05K 2203/163: Monitoring a manufacturing process - B23K: SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM - H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS - G05B: CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS (systems for controlling or regulating non-electric variables G05D; systems for regulating electric or magnetic variables G05F; control devices or systems insofar as characterised by mechanical features only G05G) ## Abstract A processor receives solder paste information, where the solder paste information describes a solder paste used in assembly of a printed circuit board. A processor determines a minimum magnetic force required for removing the solder paste from the printed circuit board based on the solder paste information. A processor receives electromagnet information, where the electromagnet information describes an electromagnet used in cleaning of a misprint of the solder paste on the printed circuit board. A processor determines a minimum amount of power to provide the electromagnet to induce the minimum magnetic force in the electromagnet, where the determination of the amount of power is based on the electromagnet information and the minimum magnetic force. A processor adjusts an amount of power applied to the electromagnet to at least the determined minimum amount of power to clean the misprint of the solder paste from the printed circuit board. ## Claims ### Claim 1 A computer program product comprising: one or more computer-readable storage media and program instructions stored on the one or more computer-readable storage media, the program instructions comprising: program instructions to receive solder paste information, wherein solder paste information includes (i) a density of a metal solder in a solder paste, (ii) a density of a flux in the solder paste, (iii) an adhesive force of the flux, and (iv) at least one magnetic property of the metal solder; program instructions to receive electromagnet information, wherein the electromagnet information describes an electromagnet used in cleaning of a misprint of the solder paste on the printed circuit board; program instructions to receive an image of the printed circuit board; program instructions to compare the image of the printed circuit board to a second image, wherein the second image depicts a printed circuit board with correctly printed solder paste; program instructions to determine at least one misprint location of the solder paste on the printed circuit board when at least one misprint is detected in response to the comparison of the image of the printed circuit board and the second image; program instructions to move the electromagnet to the at least one misprint location; program instructions to determine an amount of solder paste present in the at least one misprint location, wherein the determination of the amount of solder paste present in the at least one misprint location is based on the image of the at least one misprint location and the solder paste information; program instructions to determine a component force applied to the solder paste based on the amount of solder paste present in the at least one misprint location and the solder paste information; program instructions to determine a minimum amount of power to provide the electromagnet to induce a minimum magnetic force in the electromagnet, wherein the determination of the minimum magnetic force is based on an equation: Fm>Msg+Mfg+Fa, wherein Fm is the minimum magnetic force, Ms is the mass of metal solder in the at least one misprint location, Mf is the mass of the flux in the at least one misprint location, Fa is an adhesive force of the flux, and g is a gravitational constant; program instructions to adjust an amount of power applied to the electromagnet to at least the determined minimum amount of power to clean the misprint of the solder paste at the at least one misprint location from the printed circuit board; and program instructions to activate the electromagnet, wherein the electromagnet removes the solder paste from the at least one misprint location upon activation.