Electronic assembly remanufacturing system and method

• US 7,681,778 B2
• Filed: 11/20/2007
• Issued: 03/23/2010
• Est. Priority Date: 11/20/2007
• Status: Expired due to Fees

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Santillan Guerrero, Ernesto Nicanor, Gottshall, Paul C
• Primary Examiner(s): STONER, KILEY SHAWN
• Application Number:
  US11/943,219
• Publication Number:
  US 20090127321A1
• Time in Patent Office: 854 Days
• Field of Search: None
• US Class Current: 228/103
• CPC Class Codes: H05K 13/04 Mounting of components , e.g. of leadless components
• CPC Class Codes: H05K 2203/0763 Treating individual holes or single row of holes, e.g. by nozzle
• CPC Class Codes: H05K 2203/176 Removing, replacing or disconnecting component; Easily removable component
• CPC Class Codes: H05K 3/225 Correcting or repairing of printed circuits H05K1/0292, H05K3/222, H05K3/288, H05K3/4685 take precedence
• CPC Class Codes: H05K 3/3447 Lead-in-hole components H05K3/3415 takes precedence
• CPC Class Codes: H05K 3/3468 Applying molten solder
• CPC Class Codes: H05K 5/0034 having an overmolded housing covering the PCB
• CPC Class Codes: H05K 5/0047 having a two-part housing enclosing a PCB

Abstract

A method for remanufacturing an electronic assembly includes removing a first portion of an assembly housing to expose an underside of an enclosed circuit assembly. One or more solder joints on the underside of the circuit assembly are associated with at least one component that is also affixed to a portion of the housing. The opened electronic assembly is lowered onto a desoldering fixture having a plurality of solder pots configured to encompass, and thus desolder, the solder joints associated with the component that is affixed to a portion of the housing. Once the affected solder joints are melted, the remaining portion of the housing and the component affixed thereto may be lifted away, exposing the top surface of the circuit assembly for analysis, repair, and or adjustment.

Claims

1. A method for remanufacturing an electronic assembly, the assembly including a housing having therein a circuit assembly comprising a plurality of components, at least one of which is affixed to a portion of the housing, the method comprising:

removing a first portion of the housing to expose a portion of the circuit assembly, the exposed portion of the circuit assembly having thereon a plurality of solder joints, one or more of the solder joints being associated with at least one component affixed to a second portion of the housing for linking the at least one component to the circuit assembly;

lowering the exposed portion of the circuit assembly onto a desoldering fixture, wherein the desoldering fixture comprises a solder pot assembly including a plurality of solder pots each containing solder and having a closed upper edge, the upper edges of the pots lying essentially in a common plane and collectively encompassing a plurality of distinct regions, the solder pot assembly being registered with the exposed portion of the circuit assembly such that each solder joint associated with the at least one component affixed to the portion of the housing is aligned with only one of the plurality of distinct regions, and each solder joint not associated with the at least one component is registered with an area outside of the plurality of distinct regions; and

lifting the second portion of the housing away from the solder pot assembly while restraining the circuit assembly, thereby removing from the circuit assembly the at least one component affixed to the second portion of the housing.

2. The method according to claim 1, further comprising testing the circuit assembly to identify an improperly operating component thereon.

3. The method according to claim 2, further comprising reconditioning the circuit assembly by performing an operation selected from the group consisting of replacing the improperly operating component, repairing the improperly operating component, and adjusting the improperly operating component.

4. The method according to claim 3, further comprising reassembling the electronic assembly.

5. The method according to claim 1, wherein lowering the exposed portion of the circuit assembly onto the desoldering fixture comprises engaging one or more latches to hold the circuit assembly in place against the upper edges of the plurality of solder pots.

6. The method according to claim 5, wherein the one or more latches comprise two latches located to restrain respective opposite first and second edges of the circuit assembly.

7. The method according to claim 1, wherein lowering the exposed portion of the circuit assembly onto a desoldering fixture comprises melting the one or more solder joints associated with the component affixed to the second portion of the housing.

8. The method according to claim 7, wherein lifting the second portion of the housing away from the solder pot assembly comprises engaging a lifter assembly after the one or more solder joints associated with the component affixed to the second portion of the housing are melted.

9. A method of using and processing an engine control unit having a housing and a circuit assembly therein comprising a plurality of components, at least one of which is affixed to a portion of the housing, the method comprising:

installing the engine control unit into a machine unit;

using the engine control unit to control an engine of the machine unit;

removing the engine control unit from the machine unit;

removing a first portion of the housing to expose a portion of the circuit assembly, the exposed portion of the circuit assembly having thereon a plurality of solder joints, one or more of the solder joints being associated with at least one component affixed to a second portion of the housing for linking the at least one component to the circuit assembly;

lowering the exposed portion of the circuit assembly onto a desoldering fixture, wherein the desoldering fixture comprises a solder pot assembly including a plurality of solder pots each containing solder and having a closed upper edge, the upper edges of the pots lying essentially in a common plane and collectively encompassing a plurality of distinct regions, the solder pot assembly being registered with the exposed portion of the circuit assembly such that each solder joint associated with the at least one component affixed to the portion of the housing is aligned with only one of the plurality of distinct regions, and each solder joint not associated with the at least one component is registered with an area outside of the plurality of distinct regions;

lifting the second portion of the housing away from the solder pot assembly while restraining the circuit assembly, thereby removing from the circuit assembly the at least one component affixed to the second portion of the housing; and

testing the circuit assembly as if the at least one component had not been removed.

10. The method according to claim 9, further comprising repairing the circuit assembly.

11. The method according to claim 10, further comprising reassembling the circuit assembly and the first and second portions of the housing to form a remanufactured engine control unit and installing the remanufactured engine control unit into a machine unit.