The box that turns a battery into torque.
A battery can only give direct current. An electric motor needs three-phase alternating current whose frequency and amplitude change every millisecond as the driver asks for more or less torque. The traction inverter is the translator between the two.
Inside, six silicon-carbide power switches chop the DC link roughly 10 000 times a second, shaping three sine waves out of square pulses. It is the most electrically and thermally stressed box in the car — which is why the whole line is built around one obsession: a perfect metallurgical joint between the SiC dies and the ceramic that carries their heat away.
What is inside
six parts, and each one explains a stationRead this list once and the line stops looking like ten machines in a row — every station exists to add one of these parts, or to prove that the previous one was added correctly.
DBC substrate
Direct Bonded Copper — a thin ceramic plate with copper bonded to both faces. It insulates electrically while conducting heat, so it is the floor the whole power stage is built on. It arrives bare at I010.
SiC power dies
Six silicon-carbide MOSFETs in three half-bridges — the actual switches. SiC tolerates higher temperature and switches faster than silicon, which means lower losses, a smaller cooler and more range for the same battery.
Busbar & DC-link
A laminated copper busbar — two plates separated by a film — carries hundreds of amps with almost no stray inductance. The DC-link capacitor absorbs the switching ripple the battery must never see.
Gate-driver board
The interface between brain and muscle: it turns logic-level commands into the ±15 V gate pulses the SiC needs, across a galvanic barrier, and cuts the switch off in microseconds if it detects a short.
Housing & coolant channel
A die-cast aluminium housing with a coolant channel running directly under the power stage. Heat leaves the dies through the DBC and into the coolant — that path is the reason for every parameter at I030.
Potting resin
An encapsulation resin poured over the electronics. It holds everything against vibration, keeps humidity out and suppresses partial discharge at high voltage — the reason the box survives fifteen years under a car.
The rhythm of the line
cycle time per stationTen stations, ten different cycle times. The line can only go as fast as its slowest station — I030 sinter / reflow at 130 s — so that one dwell sets the takt for everyone: 27.7 inverters per hour, or one every 130 seconds. Every faster station spends part of its day waiting, on purpose.
This is why the live view shows stations sitting in idle or blocked and it is not a problem: buffers between stations are capped at three pieces, so instead of building a mountain of work-in-progress, the fast stations are held back by the bottleneck. Total work content is 11.4 min per inverter across the ten stations — but a finished unit still comes off the line every 130 s.
Station by station
what happens, and what it takes to get it rightEach block below gives the short version first. Open Process detail for the material consumed, the machine, the parameters the station actually runs to, what typically breaks it, and what makes a piece fail.
Where it goes next
from I060 to the e-axleA tested inverter is not the end product. It is one of the three big parts of an e-axle — motor, gearbox, inverter — and it leaves this line to be married to the other two in the assembly hall.
The buffer is what decouples the two lines. If the inverter line stops, the e-axle line keeps building until the buffer runs dry — then A044 starves and the whole assembly hall waits. If the inverter line runs ahead and the buffer fills to its maximum, the surplus is palletised as finished goods (PALINV-, eight per pallet) and shipped out instead.
Process parameters, fault distributions and cycle times on this page are the ones the simulated line actually runs to — the same values that drive the live view. The line is a generic EV traction-inverter reference, not a copy of any manufacturer's process.