Battery module and pack manufacturing · reference card
Tab and busbar welds are small, fast and numerous. What a thermal and process record shows on each one, how a one-cell pilot runs and what goes into the quality file.
Tab and busbar welds are short, fast and repeated hundreds of times in a module. A record made while each weld runs covers every joint, including the ones no sample plan reaches.
The welding monitoring system page compares the HeatCore tiers.
Start with one cell and one joint family, for example tab to busbar on one module type. Fix scope, reference and false-alarm counting first, using the pilot acceptance checklist. Seeded faults such as a deliberate gap or reduced power show what the record separates and what it does not.
Monitoring does not replace the tests the buyer specifies. It joins program, station, thermal record and test result under one identifier per weld. The laser welding guide for battery lines covers the process in more depth.
| Code | Why it applies |
|---|---|
| ISO 13919-2 | Quality levels for imperfections in laser-welded joints in aluminium and its alloys and in pure copper, the two tab and busbar materials. |
| ISO 15614-11 | Procedure qualification testing for electron and laser beam welding. |
| ISO 3834-2 | The welding quality system an automotive buyer commonly expects behind the process. |
| Customer-specific requirements | Battery buyers set their own limits on joint resistance, pull strength and the records kept per module. |
| Pain point | Consequence | Signal that sees it |
|---|---|---|
| A module carries hundreds of welds and each one is in the current path | A single weak joint raises resistance and heats in service, and sampling by pull test checks only a few of them. | A thermal record of every weld, compared with a reference built from good welds on the same joint. |
| Copper and aluminium tabs are thin and the window between a cold weld and burn-through is narrow | Too little energy leaves the tab unbonded; too much damages the cell underneath. | Peak temperature and cooling behaviour per weld, which move in opposite directions for the two faults. |
| Gaps between tab and busbar change from part to part | The same program gives a different joint, and the cause is clamping, not the laser. | Heat distribution across the joint, where a gap shows as an asymmetric or shortened footprint. |
| A returned module has to be traced to its welds | Without a record per weld the investigation covers the whole lot. | Weld identifier, station, program and thermal record joined automatically and retained. |
No. Destructive and electrical checks remain as the buyer specifies. The record covers every weld between those checks, so a drift is seen when it starts.
The thermal record described here is for laser and resistance welds. Ultrasonic welding is assessed per cell during the pilot, and no result is promised before it is measured.
With a pilot on one cell and one joint family, acceptance criteria fixed beforehand, and scaling only once they are met.
Therness measures what happens while the arc is running — parameters, thermal signature, per-weld records — so the problems on this page surface on the shift that made them.
Progetto cofinanziato nell'ambito del PR Piemonte FSE+ 2021-2027,
Priorità I, Obiettivo Specifico a), Azione 4 – "Sostegno alla nascita delle start up"
