Check board heat history and neighboring component limits before reworking an SMT busbar or power terminal, then develop a local profile for that board and equipment. Hot-air settings do not equal joint temperature, and a heat-tolerant conductor does not establish further rework capability for the board.
List the board's previous thermal processes
Record single- or double-sided reflow, earlier rework, replacements, baking and opening history; check component data sheets and moisture requirements. TI's power-module guidance highlights allowed reflow cycles, temperature limits and prior board reflows during rework.
That guidance addresses its power modules. Use the principle to establish a board heat-history list, but check limits separately for busbars, terminals, connectors, insulation and other devices. Do not assign a universal rework count without component requirements.
Measure the local profile on a representative board
Develop the process with representative PCB construction, copper, conductor mass, orientation, nozzle and underside heating. Measure target joints, nearby temperature-sensitive parts and board surfaces to detect a conflict between incomplete melting and surrounding overheating.
TI's WiLink 8Q package guide calls for profiling each PCB design on the actual rework station because board thermal density and equipment heat transfer differ. Use that process principle, not its package-specific temperature limits for unrelated parts.
Control removal and replacement
Specify board support, removal direction, solder cleanup, land inspection, fresh solder application, alignment and reflow. Avoid transferring mechanical force into joints that have not fully melted; validate support and lifting for heavy conductors on sample boards.
Before replacement inspect lifted lands, barrel or laminate damage, mask changes and nearby component movement. Cleaning and baking must suit board materials and component requirements. Escalate laminate damage for repair review rather than concealing it with extra solder.
- Retain before-and-after images, profiles, procedure and board ID
- Inspect target joints, coplanarity, insulation position and nearby components
- Retest continuity, resistance, function and loaded temperature rise as the project requires
Frequently asked questions
Can a removed busbar be reused immediately? Review finish, deformation, coplanarity and contamination and confirm that supplier and project requirements permit reuse.
Does a passing functional check release a repaired board? A short functional test may not cover land damage, local resistance or thermal reliability. Use an approved repair-validation plan.
Include service access in the design RFQ
Provide PCB stackup, lands, conductor mass, nearby components, tool access and expected repair route. Review assembly and rework support, inspection and traceability before production to avoid discovering inaccessible joints later.
Apply this guide to a project
Use product pages to identify the hardware family and the calculator for early estimates only. Acceptance depends on drawings, operating conditions and project tests.